Method for manufacturing multilayer body, multilayer body, and method and system for authenticating multilayer body

Abstract

The invention relates to a method for producing a multilayer body (1), in particular a laminated film or a transfer film, in which a copy layer (12) is applied to a carrier layer (11) and a first graphic code (21) is Fourier-transformed into a two-dimensional Fourier pattern (23) and the two-dimensional Fourier pattern (23) is binarized in order to obtain a binarized two-dimensional Fourier pattern (24), and transferring the binarized two-dimensional Fourier pattern (24) onto an embossing tool, and molding the binarized two-dimensional Fourier pattern (24) as an embossed structure at least partially into the replica layer (12) in the first region by means of the embossing tool.

Description

[0001] The invention relates to a method for producing a multilayer body and to a multilayer body. The invention also relates to a method for authenticating a multilayer body and to an authentication system.

[0002] It is known to equip multilayer bodies with security features that protect against counterfeiting. In addition to a series of holograms, Fourier patterns are also suitable for this.

[0003] From DE 102017206466 A1, a method for producing a security feature is known in which a machine-readable graphic code is provided, the graphic code being embedded in a two-dimensional discrete complex function, which is Fourier transformed and binarized to form a two-dimensional image. The binarized Fourier image is printed with a sufficiently high pixel resolution so that, in the case of a copy of the binarized Fourier image with a maximum scanning or printing resolution of 600x600 dpi by a conventional printer and copier, the machine-readable graphic code is no longer readable after the inverse transformation. The scanning or printing resolution of 600x600 dpi refers to the data printed by the printer. The dpi values ​​specified in the case of conventional printers and copiers are not always achievable in practice.

[0004] However, a disadvantage of the known method and multilayer body is that the Fourier pattern is applied by digital printing. Therefore, such multilayer bodies are basically easy to imitate and copy by skilled personnel using professional equipment (so-called expert copy), in particular professional equipment with a scanning or printing resolution of more than 600 dpi.

[0005] It is currently an object of the present invention to provide a method for producing a multilayer body and a multilayer body in which the protection against counterfeiting is increased, the production moreover being not restricted to digital printing methods.

[0006] This object is achieved by a method for producing a multilayer body, in particular a laminated film or a transfer film, wherein a replication layer is applied to a carrier layer, and a first graphic code is Fourier transformed into a two-dimensional Fourier pattern, and the two-dimensional Fourier pattern is binarized to obtain a binarized two-dimensional Fourier pattern, and the binarized two-dimensional Fourier pattern is transferred to an embossing tool, and the binarized two-dimensional Fourier pattern is molded into the replication layer as an embossed structure at least partially in a first area by the embossing tool.

[0007] This object is further achieved by a multilayer body (in particular a laminated film or a transfer film) preferably prepared according to one of claims 1 to 32, wherein the multilayer body has a carrier layer and a replication layer arranged thereon, wherein an embedded first graphic code which is Fourier transformed into a binarized two-dimensional Fourier pattern is molded as an embossed structure at least partially in a first area in the replication layer.

[0008] The object is also achieved by a method for authenticating a multilayer body (in particular a multilayer body according to one of claims 33 to 52, and particularly preferably a multilayer body prepared by a method according to claims 1 to 32), using an authentication system, by reading an image of a binarized two-dimensional Fourier pattern of the multilayer body with a camera of a mobile terminal, performing an inverse Fourier transform on the read image, providing the inverse Fourier transform image to a first reading algorithm of a first graphic code, reading out the first graphic code and detecting the first graphic code.

[0009] Furthermore, the object is achieved by an authentication system for authenticating a multilayer body according to one of claims 33 to 52, in particular a multilayer body produced by a method according to one of claims 1 to 32,

[0010] - comprising a mobile terminal with a camera and a transceiver unit, wherein the mobile terminal with a camera is used to read an image of a binarized two-dimensional Fourier pattern (24) of a multilayer body (1) protected against counterfeiting, and the transceiver unit can transmit the data of the multilayer body (1) read by the camera to an authentication server,

[0011] - Inverse Fourier transform program, which can be used to perform inverse Fourier transform on the binarized two-dimensional Fourier pattern,

[0012] - a first reading algorithm for a first graphical code, said first graphical code being read out from an inverse Fourier transformed image,

[0013] - includes an authentication server, which is in data transmission connection with the mobile terminal, and the read first graphic code placed on the multi-layer body, in particular the batch number, is stored on the authentication server, and the read first graphic code, in particular the batch number, sent by the mobile terminal can be authenticated on the authentication server, and the authentication server can output an authentication signal to the mobile terminal.

[0014] It has been shown here that by means of a multilayer body according to the invention, a method for producing a multilayer body according to the invention, a method for authenticating a multilayer body and an authentication system, a multilayer body is obtained in which a first graphic code is contained in a binarized two-dimensional Fourier pattern. The binarized two-dimensional Fourier pattern is introduced into the multilayer body as an embossed structure. The binarized two-dimensional Fourier pattern can therefore be read out by the authentication system and at the same time, due to the optical variability brought about by the embossed structure, an enhanced anti-counterfeiting protection is provided for the binarized two-dimensional Fourier pattern. Due to the optical variability, it is not possible to copy the binarized two-dimensional Fourier pattern using conventional printing or copying.

[0015] Furthermore, with the multilayer body according to the invention and the method according to the invention for producing a multilayer body, a multilayer body is obtained in which no two-dimensional Fourier pattern of binarization is introduced or applied by digital printing. In the case of applying Fourier patterns by digital printing, it has been necessary until now to print these Fourier patterns in part with a printing resolution of up to 1200 dpi. In order to be able to print such a high resolution with high quality, very expensive printers are required. With the multilayer body according to the invention and the method according to the invention for producing a multilayer body, it is now possible to introduce Fourier patterns into a multilayer body without digital printing.

[0016] In addition, the binarized two-dimensional Fourier pattern provided as an embossed structure provides such an advantage that it can be read by a conventional mobile terminal and read out by suitable software. For reading, the camera of a commercially available smartphone is sufficient. This is due to the fact that only the binarized two-dimensional Fourier pattern is read as a normal picture by the camera. Unlike, for example, when a computer-generated hologram is read out, the light directly diffracted by the Fourier pattern is not read. In the case of a computer-generated hologram (CGH), it is necessary to read these holograms by diffraction on the hologram structure with the aid of a monochromatic laser. To this end, the lateral structure of the CGH needs to be on the order of magnitude of the wavelength of the light used, because otherwise the light cannot be effectively diffracted. For example, the structure of the CGH basically needs to have a size of 500nm to up to 10μm. This corresponds to an effective resolution of 50,000dpi to 2500dpi. In contrast to the structure of the CGH, in the case of a binarized two-dimensional Fourier pattern, there is a lower resolution. The effective resolution of the binarized two-dimensional Fourier pattern is preferably at most 2500 dpi, preferably at most 1200 dpi, particularly preferably at most 900 dpi. A lower resolution is necessary so that the structure can actually also be read by commercially available cameras with the aid of ordinary imaging. An effective resolution of the binarized two-dimensional Fourier pattern of 650 dpi is usually used for recognition using commercially available cameras. Although a binarized two-dimensional Fourier pattern with a resolution of 650 dpi can be generated by a printer / scanner with a scanning or printing resolution of at least 650 dpi, the generated copies will not be optically variable.

[0017] Furthermore, the binarized two-dimensional Fourier pattern is preferably molded with an effective resolution of at most 2500 dpi, preferably at most 1200 dpi, particularly preferably at most 900 dpi.

[0018] Further advantageous embodiments of the invention are described in the dependent claims.

[0019] Since the multilayer body can be designed as a laminating film, a transfer film, in particular a hot stamping film or a cold stamping film, the multilayer body can be used for various intended purposes. For example, the multilayer body is used in the packaging industry to decorate packaging for anti-counterfeiting protection. However, the multilayer body can also be used to protect security documents, such as identity cards, passports, etc., or also securities. In addition, the multilayer body is used wherever it is necessary to verify the authenticity of the product. This is because the authenticity of the product can be detected by means of a machine-readable binary two-dimensional Fourier pattern, in which the first graphic code is again embedded.

[0020] Here, packaging is a general term referring to the sales packaging of a product (e.g. a toothpaste tube) and the outer packaging (e.g. a folding box for a product). A packaging can also be a part of a packaging item, such as a label affixed to an outer packaging item. A packaging item can also be a box, etc., in which multiple outer packaging items of a product are packaged.

[0021] In this context, transparent is understood to mean a range having a transmittance of more than 50%, preferably more than 70%, particularly preferably more than 80%, in particular in the wavelength range of light visible to a human observer.

[0022] In this context, opaque is understood to mean a range having a transmittance of less than 40%, preferably less than 30%, particularly preferably less than 20%, in particular in the wavelength range of light visible to a human observer.

[0023] First, the generation of the Fourier pattern will be described in more detail below.

[0024] The machine-readable first graphical code is embedded in a real amplitude function of a two-dimensional discrete complex function G(fx,fy) having a frequency coordinate of fx and a frequency coordinate of fy. Thus, for embedding, the code is placed in a two-dimensional (preferably square) image template, wherein the x and y values ​​of the image template are interpreted as fx and fy frequencies.

[0025] In principle, a complex number or a complex function can be represented as the sum of a real and an imaginary part or as the sum of a real and an imaginary function, or in polar notation as the product of a magnitude function and a phase function.

[0026] The method according to the invention starts with providing a machine-readable first graphical code as an amplitude function of a two-dimensional discrete complex function G(fx, fy). The amplitude function preferably has a function value of 0 or a function value of 1 at two frequency coordinates fx and fy. Function value 1 is particularly represented by a black coordinate point of the code located in the image template, and function value 0 is particularly represented by a white coordinate point of the code located in the image template. Here, the highest frequency used in the fx or fy direction is preferably at least 600 dpi.

[0027] Preferably, a suitable phase function is added by multiplication Add to the real magnitude function.

[0028] The purpose of the phase function is to smooth the spectrum of the magnitude function.

[0029] Phase function It can be a random phase. Preferably, the first graphic code for generating the phase function is first formed as a random grayscale image. The outline of the grayscale image corresponds to the first graphic code, except that the values ​​are not 0 (white) and 1 (black) as in the construction of the amplitude function, but random grayscale values ​​between white and black. The grayscale values ​​are assigned to numbers between 0 and 2π. If the grayscale value is black, the phase is 2π, and if the grayscale value is white, the phase is 0. The other grayscale values ​​are assigned to angles between 0 and 2π (radians) according to the grayscale. The darker the color, that is, the darker, the larger the angle. In this way, the random grayscale image can be clearly converted into a phase function And the complex-valued function G(fx,fy) is found by multiplying the amplitude function by the phase function. The random phase also provides the advantage that a random phase is assigned to each frequency range, whereby the subsequent Fourier pattern becomes easier to read.

[0030] However, other phase functions may also be added to the real amplitude function.

[0031] The two-dimensional discrete complex function G(fx,fy) is then Fourier transformed, and the resulting Fourier transform g(x,y) is binarized to form a two-dimensional image. For binarization, the real part of the Fourier transform g(x,y) can be determined and binarized with the aid of a threshold. The real part of the Fourier transform again contains the grayscale. Binarization of the image here means that the value 1 is assigned to each pixel of the image whose grayscale is above the threshold, and the value 0 is assigned to each pixel whose grayscale is below the threshold. 10% binarization means that 10% of the pixels are black and 90% of the pixels are white. 50% binarization means that 50% of the pixels are black, 50% of the pixels are white, and so on. Alternatively, the imaginary part or phase of the Fourier transform g(x,y) can also be determined and binarized with the aid of a threshold. Other binarization possibilities are known in the prior art (Goodman, JW, Introduction to Fourier Optics, McGraw-Hill (New York) (1996)).

[0032] The real part of the Fourier transform is preferably binarized, and a binarized two-dimensional Fourier pattern is formed therefrom.

[0033] The binarized two-dimensional Fourier pattern is preferably generated with a binarization of less than 50%, preferably less than 20%. The binarization is typically about 15%.

[0034] The carrier layer consists in particular of a self-supporting material and / or a plastic-like substance. The carrier layer is preferably selected as a composite material from the following material classes, either individually or in combination: PET; polyolefins, in particular polyolefins from the group consisting of OPP, BOPP, MOPP, PP, PE; PMMA; PEN; PA; ABS. The carrier layer may also have been pre-coated by the manufacturer and the multilayer body may be constructed on this pre-coated material. The carrier layer may also be a biodegradable and / or compostable carrier layer. EVOH is preferably used here.

[0035] The layer thickness of the carrier layer is advantageously between 4 μm and 500 μm, in particular between 4.7 μm and 250 μm.

[0036] The multilayer body can be formed as a laminate film having a carrier layer and a plurality of useful layers, for example a plurality of decorative layers, and an adhesive layer, in particular a heat-activatable adhesive layer, wherein the carrier layer and the useful layers are bonded to each other in the form of an embossed layer. are arranged together in the form of on a target substrate.

[0037] In particular, the multilayer body is formed as a transfer film. The transfer film in particular has a transfer layer (transfer layer) which is preferably formed from several layers, wherein the layers are in particular selected individually or in multiples or in combination from: adhesive layer, adhesion promoter layer, primer layer, barrier layer, compensation layer, metal layer, oxide layer, color layer, replication layer, protective layer.

[0038] The transfer film also has a carrier layer, wherein the transfer layer can be peeled off from the carrier layer. In order to peel off the transfer layer more easily, a peeling layer can be arranged between the transfer layer and the carrier layer.

[0039] Preferably, a release layer and / or a protective layer is applied to the carrier layer, in particular wherein the release layer and / or the protective layer is arranged between the carrier layer and the replication layer.

[0040] The peeling layer in particular ensures that the layer of the multilayer body can be separated from the carrier layer non-destructively as a transfer layer. The peeling layer is preferably formed by wax, polyethylene (PE), polypropylene (PP), cellulose derivatives and / or poly (organic) siloxanes. The above-mentioned wax can be a natural wax, a synthetic wax or a combination thereof. The above-mentioned wax is, for example, carnauba wax. The above-mentioned cellulose derivative is, for example, cellulose acetate (CA), cellulose nitrate (CN), cellulose acetate butyrate (CAB) or a mixture thereof. The above-mentioned poly (organic) siloxane is, for example, a silicone adhesive, a polysiloxane adhesive or a mixture thereof. The peeling layer preferably has a layer thickness between 1 nm and 500 nm, in particular a layer thickness between 5 nm and 250 nm, and particularly preferably a layer thickness between 10 nm and 250 nm.

[0041] When the multilayer body is used as a laminating film, for example for label and / or sticker applications, the connection between the carrier layer and the subsequent layer or one or more useful layers is usually maintained during application. Therefore, in the case of laminating films, the release layer is basically omitted or, for example in the case of laminating films for security applications, the release layer is designed so that separation of the carrier layer from the useful layer can preferably only take place after application.

[0042] The release layer can be produced by known printing methods. In particular, gravure printing, flexographic printing, screen printing, inkjet printing or application by means of a slit nozzle are suitable. However, the release layer can also be formed by vapor deposition, physical vapor deposition (PVD), chemical vapor deposition (CVD) and / or sputtering deposition.

[0043] The protective layer is preferably a thermoplastic layer or a heat-cured layer or a radiation-cured layer of a varnish, which is selected from PMMA, PVC, melamine, acrylates, polyurethanes, crosslinkers, photoinitiators, additives, defoamers, leveling agents, wetting agents, individually, in multiple sublayers and / or as a mixture. The protective layer can also be composed of radiation-curable dual-cured varnishes. This dual-cured varnish can be thermally pre-crosslinked in the first step during and / or after application in liquid form. Preferably, in the second step, in particular after processing the multilayer film, the dual-cured varnish is radiation-post-crosslinked by high-energy radiation (preferably UV radiation). This type of dual-cured varnish can be composed of different polymers or oligomers, which have unsaturated acrylate or methacrylate groups. These functional groups can be radiation-crosslinked to each other in particular in the second step. For the thermal pre-crosslinking in the first step, it is advantageous that at least two or more alcohol groups are also present in the case of these polymers or oligomers. These alcohol groups can be crosslinked with multifunctional isocyanates or melamine formaldehyde resins. Various UV raw materials such as epoxy acrylates, polyether acrylates, polyester acrylates and in particular acrylic acrylates are preferably suitable as unsaturated oligomers or polymers. Isocyanates are suitable as blocked and unblocked representatives based on TDI (TDI = toluene-2,4-diisocyanate), HDI (HDI = hexamethylene diisocyanate) or IPDI (IPDI = isophorone diisocyanate). Melamine crosslinkers can be in fully etherified form, of the imino type or as benzoguanamine representatives.

[0044] The protective layer preferably has a layer thickness of between 50 nm and 30 μm, preferably between 1 μm and 3 μm. The protective layer can be produced by gravure printing, flexographic printing, screen printing, inkjet printing, by means of a slot nozzle and / or by vapor deposition, in particular by physical vapor deposition (PVD), chemical vapor deposition (CVD) and / or sputtering deposition. In particular, vapor deposition is performed in the case of thinner protective layers below 1 μm.

[0045] In particular, preferably after the replication varnish has cured, the metal layer and / or the HRI layer and / or the primer layer and / or the adhesive layer can be applied partially or over the entire surface to the replication layer. In addition, the metal layer and / or the HRI layer and / or the primer layer and / or the adhesive layer can also be arranged on the replication layer.

[0046] The metal layer can be applied both over the entire surface and in local areas. The metal layer can preferably be patterned and present a pattern and / or a motif, and in particular the pattern and / or the decorative pattern can also be arranged in register with the embossed structure of the print (Druck) and / or the replica layer. In addition, the metal layer can also be arranged at least partially or over the entire surface in the first area. As described above, the embossed structure of the binarized two-dimensional Fourier pattern is at least partially arranged in the first area. Since the metal layer is also arranged in the first area, it is ensured that the binarized two-dimensional Fourier pattern is metallized, thereby obtaining a metallic appearance.

[0047] Preferably, it is also provided that the metal layer is formed in register with the embossed structure.

[0048] Registered or register or precise registration or precise registration or registration accuracy or registration accuracy means the positional accuracy of two or more layers relative to each other. The registration accuracy should be within a predetermined tolerance range, which should be as small as possible. At the same time, in order to improve process reliability and / or product quality and / or anti-counterfeiting protection, the registration accuracy of multiple elements and / or layers relative to each other is an important feature. Positionally accurate positioning can be achieved in particular by perceptible, preferably optically detectable registration marks or registration marks. These registration marks or registration marks can represent specific independent elements or regions or layers, or they themselves are parts of the elements or regions or layers to be positioned.

[0049] The metal layer is preferably formed alone or as an alloy or eutectic alloy (selected from aluminum, chromium, gold, copper, tin, indium, silver). The metal layer is preferably produced by vapor deposition, in particular by vacuum vapor deposition. The vapor-deposited metal layer can be realized on the entire surface and optionally retained on the entire surface, or constructed and thus only partially present with known demetallization methods such as etching, stripping (paint washing method) or photolithography. The layer thickness of the metal layer is particularly between 10nm and 500nm.

[0050] However, the metal layer can also consist of a printed layer, in particular of a printed layer of metal pigments in a binder. These printed metal pigments can be applied to the entire surface or to a portion of the surface and / or have different colors in different areas of the surface. The layer thickness of the metal layer of metal pigments is in particular between 1 μm and 10 μm.

[0051] The metal layer can also be produced from a varnish having electrically conductive metal pigments, in particular by printing and / or pouring them thereon.

[0052] Alternatively, HRI or LRI layers (high refractive index - HRI, low refractive index - LRI) can also be used instead of metal layers. Such dielectric HRI or LRI layers consist of vapor deposited layers of, for example, metal oxides, metal sulfides, titanium oxide, etc. The layer thickness of such layers is preferably 10 nm to 500 nm.

[0053] In addition, a first metal layer of semi-transparent design can also be provided as a filter layer. Such a metal layer consists of, for example, a vapor-deposited layer of a thin metal (Al, Cr) or a thinly coated metal oxide, metal sulfide, silicon oxide, etc. The layer thickness of such a layer is selected so that the optical density is in particular in the range of 0.1 to 0.9 OD (OD=optical density). The subsequent dielectric spacer layer required for the thin-film color tilt effect can be applied similarly to the replication layer, wherein the layer thickness range is preferably between 0.1 μm and 1.0 μm, and / or its composition corresponds in particular to the replication layer. In this case, the spacer layer can also be used directly as a replication layer. The spacer layer can also be vapor-deposited as a ceramic spacer layer. Typically, metal or semi-metal oxides such as SiO2, TiO2, Na3AlF6 or MgF2 are vapor-deposited according to one of the methods also mentioned for the metal layer. The layer thickness here is in particular between 20 nm and 500 nm. The spacer layer can also be printed on as a transparent varnish layer.

[0054] Such a filter layer can also be applied before the replication layer. The replication layer is then used in particular as a dielectric spacing layer, with the layer thickness preferably ranging between 0.1 μm and 1.0 μm.

[0055] This is followed by a dielectric spacer layer, in particular an opaque or semi-transparent metal layer, which is vapour deposited as described above.

[0056] The adhesive layer and / or the primer layer are preferably formed from a varnish which is selected, alone, in a plurality of sub-layers and / or as a mixture, from the group consisting of: PMMA, PVC, acrylates, polyamides, polyvinyl acetates, hydrocarbon resins, polyesters, polyurethanes, chlorinated polyolefins, polypropylene, epoxy resins, polyurethane polyols, in particular in combination with non-activated isocyanates, fillers such as SiO2 and / or TiO2. In addition to the adhesive layer, a primer layer may also be provided.

[0057] The layer thickness of the adhesive layer and / or primer layer is preferably between 0.5 μm and 20 μm, particularly preferably between 1.5 μm and 5 μm. The adhesive layer and / or primer layer can be produced by gravure printing, flexographic printing, screen printing, inkjet printing and / or application by slit nozzles.

[0058] The replication layer preferably has a binarized two-dimensional Fourier pattern as an embossed structure at least partially on one of its upper sides. The replication layer is preferably formed from a thermoplastic varnish or a radiation-curing varnish which is selected from the group consisting of acrylates, cellulose, PMMA, polyurethane, isocyanates, either alone, in a plurality of sub-layers and / or as a mixture. The surface structure is preferably molded into the thermoplastic replication layer by means of heat and pressure by the action of an embossing tool.

[0059] Furthermore, the replication layer can also have a UV-curable replication varnish, which is pre-cured or fully cured by UV radiation after the molding of the embossed structure. The embossed structure is molded into the not yet finally cured replication layer by the action of the embossing tool, and the replication layer is cured by irradiation with UV light during or directly after molding. Additional UV irradiation can be carried out before and / or during molding.

[0060] In principle, the replication layer can be produced by known printing methods. In particular, gravure printing, flexographic printing, screen printing or inkjet printing are suitable. However, production by slit nozzles is also possible.

[0061] Preferably, the binary two-dimensional Fourier pattern (24) is designed to be provided as a nanostructure and / or a microstructure, in particular as a diffraction grating, a scattering matte structure, a reflective surface and / or a reflective microstructure. In addition, the binary two-dimensional Fourier pattern can also be molded into the replication layer as a nanostructure and / or a microstructure, in particular as a diffraction grating, a scattering matte structure, a reflective surface and / or a reflective microstructure.

[0062] As has been further described above with respect to the generation of the Fourier pattern, the binarized two-dimensional Fourier pattern is preferably formed by bright pixels and dark pixels. These bright pixels and dark pixels are preferably arranged in a two-dimensional grid with a resolution of M×N pixels.

[0063] It has been shown that commercially available printers have a printing resolution of about 600 dpi, with the result that when the binarized two-dimensional Fourier pattern is photographed and the photographed binarized two-dimensional Fourier pattern is printed out again, so much information is lost that it is no longer possible to reconstruct the first graphic code. If the binarized two-dimensional Fourier pattern is to be copied and the information contained therein is to be retained, at least the effective resolution of the binarized two-dimensional Fourier pattern must be maintained during the copying process. For example, if during the copying process the resolution of the scanner used or the printer used is lower than the effective resolution of the binarized two-dimensional Fourier pattern, the binarized two-dimensional Fourier pattern is only incompletely copied and the first graphic code contained therein is damaged and, as a result, is no longer readable. It has been shown that, in the case of the above-mentioned pixel sizes, protection against copying using commercially available office copiers is guaranteed. However, because the binarized two-dimensional Fourier pattern is designed as an embossed structure, the optical variability of the binarized two-dimensional Fourier pattern due to the embossed structure cannot be imitated by a copier, thereby further enhancing the anti-counterfeiting protection.

[0064] The effective resolution is preferably the resolution that a binarized two-dimensional Fourier pattern has.The effective equivalent resolution is preferably the resolution that a binarized two-dimensional Fourier pattern introduced into the embossed structure has.

[0065] The effective equivalent resolution of the binarized two-dimensional Fourier pattern introduced into the embossed structure is determined by the positioning of the first graphic code within the image template, which is done before the Fourier transformation. The horizontal and vertical axes of the image template are interpreted here as (spatial) frequency axes. Frequency 0 is located in the center of the image template, and the highest frequency fx_limit or fy_limit achievable during the stamping process is located at the edge of the image template. The positioning of the first graphic code within the image template in the fx and fy directions establishes the maximum horizontal spacing fx_max of the first graphic code from the center of the image and the maximum vertical spacing fy_max of the first graphic code from the center of the image. The quotients fx_max / fx_limit and fy_max / fy_limit are formed. The effective resolution in the x direction is the product of the quotient fx_max / fx_limit multiplied by the resolution used in the stamping process,

[0066]

[0067] The effective resolution in the y direction is the product of the quotient fy_max / fy_limit times the resolution used during the stamping process.

[0068]

[0069] The maximum effective resolution is the greater of the effective resolution in the x-direction and the effective resolution in the y-direction. The first graphic code is preferably placed so far outside the image template that the fx_max or fy_max value is so large that the maximum effective equivalent resolution is higher than 600 dpi. If the first graphic code is, for example, placed exactly at the edge of the image template, the maximum effective equivalent resolution corresponds exactly to the resolution used for the stamping process. If the first graphic code is, for example, placed halfway between the center and the edge of the image template, the maximum effective equivalent resolution corresponds exactly to half the resolution used for the stamping process.

[0070] At the same time, it is preferred that the maximum effective equivalent resolution is at most as large as the general resolution of the camera of the authentication system. In particular in the case of mobile authentication systems, the maximum effective equivalent resolution should be lower than 1200 dpi.

[0071] In particular, the bright pixels and the dark pixels can be formed by diffraction gratings, wherein the gratings of the bright pixels and the dark pixels are distinguished from each other by the grating period and / or the grating depth and / or the orientation. The grating can be a linear grating or a cross grating or a serpentine grating, or can also include more complex variations. The profile shape can be sinusoidal, blazed or more complex.

[0072] Furthermore, the grating period of the diffraction grating may be in the range of 200 nm to 20 μm, preferably in the range of 250 nm to 10 μm, and / or the grating depth of the diffraction grating may be in the range of 50 nm to 2 μm, and / or the grating depth of the diffraction grating may be 5% to 20% of the grating period.

[0073] If the contrast between the diffraction gratings of bright and dark pixels is produced by different grating periods, the difference in the period is preferably at least 20 nm, further preferably at least 50 nm, particularly preferably at least 100 nm.

[0074] In an embodiment, the grating is a sinusoidal linear or serpentine grating, wherein the orientations of the grating lines in the bright and dark pixels differ by at least 30°, preferably more than 45°, further preferably at least 60°, in particular by almost 90°.

[0075] Optionally, it can also be designed that the bright pixels and dark pixels are formed by structures that appear bright or dark in direct reflection, wherein the dark structure includes a high-frequency and deep cross-grating structure and / or a cross-grating and / or a hexagonal grating and / or a reflector, and / or wherein the bright structure includes a static and / or dynamic matte structure and / or a Fourier hologram. Here, the dark structure can be color-neutral, i.e. dark gray to black, or it can also be dark, such as dark red. The bright structure can also be color-neutral, i.e. light gray to white, such as gold.

[0076] The dark-appearing structure is preferably formed by a reflector or a high-frequency deep cross-grating structure, also called a sub-wavelength grating. Preferably, the grating period of the cross-grating and / or hexagonal grating can be in the range of 200nm to 450nm, and the grating depth of the cross-grating and / or hexagonal grating can be greater than 150nm. Cross-gratings and / or hexagonal gratings offer the advantage that they show a stronger color impression than linear gratings. This is particularly advantageous when the binarized two-dimensional Fourier pattern is to be designed in color.

[0077] In addition, it is preferred that the average spacing of the matte structures is in the range of 500nm to 5μm, and the average depth of the matte structures is in the range of 100nm to 2μm.

[0078] Alternatively, it is also conceivable that the light pixels and the dark pixels are formed by blazed gratings, wherein the orientation of the blazed gratings in the light pixels and the dark pixels differs by at least 150°, in particular by about 180°. It is preferably provided that the grating period of the blazed gratings is in the range of 3 μm to 20 μm and / or the grating depth of the blazed gratings is in the range of 500 nm to 2 μm. This results in a white appearance, and such blazed gratings can also be thermally replicated well.

[0079] In order to compensate for the surface roughness of the target substrate, the multilayer body may also include at least one compensation layer, which is preferably arranged between the replication layer and the adhesive layer or primer layer, or between the metal layer and the adhesive layer or primer layer. Such a compensation layer is used in particular when the multilayer body or the transfer layer of the multilayer body is applied to a target substrate with a relatively high surface roughness, such as uncoated cardboard or uncoated paper. The reading and readout of the binarized two-dimensional Fourier pattern by means of a mobile terminal is improved by the compensation layer. It is also possible to provide a plurality of compensation layers, in particular between different layers of the transfer layer. For example, between the adhesive layer and the primer layer.

[0080] The compensation layer can be produced by gravure printing, flexographic printing, screen printing, inkjet printing, by means of a slot nozzle and / or by vapor deposition, in particular by physical vapor deposition (PVD), chemical vapor deposition (CVD) and / or sputtering deposition.

[0081] The compensation layer preferably has a layer thickness in the range from 5 μm to 20 μm.

[0082] The compensation layer can in particular comprise materials selected from the group consisting of: acrylates, polyurethanes, nitrocellulose, fillers, additives, either alone or in combination.

[0083] If the multilayer body is a hot stamping film Then the compensation of the surface roughness can also be achieved preferably by smoothing pre-printing on the substrate. This is particularly advantageous when the target substrate is paper or paperboard. Due to the pre-printing on the substrate, so-called coated paper or coated paperboard is obtained. The pre-printing on the substrate is preferably the deposition of an adhesive, which makes the surface of the paper or paperboard smooth. The adhesive preferably contains one or more components selected from chalk, kaolin, calcium carbonate. Preferably, the adhesive is applied uniformly to the entire surface of the paper or paperboard by a scraper, thereby sealing the surface. Optionally, the paperboard or paper can then also be guided through a calender, during which the surface of the paperboard or paper is smoothed and calendered by means of a roller under the action of heat and pressure. Due to the smooth surface of the target substrate, after applying the transfer layer of the multilayer body or multilayer body, the two-dimensional Fourier pattern of the binarization appears more intense, which is easier to read for mobile terminals even in the case of poor lighting quality.

[0084] Optionally, when the multilayer body is used as a hot stamping film for a target substrate, in particular an uncoated cardboard or uncoated paper, the surface of the target substrate can be provided to be coated with water glass. Water glass is a term used to describe glassy, ​​amorphous, water-soluble sodium, potassium and / or lithium silicic acid or its aqueous solution that solidifies from a melt. In order to be able to apply solid water glass to paper or cardboard, it is first ground into a powder. Thereby, liquid water glass (so-called liquid glass) is obtained in the form of a transparent colloidal alkaline solution or also in the form of an alkaline gel by dissolving in water at high temperature (in particular in the range of 100° C. to 200° C.) and high pressure (in particular in the range of 1 bar to 8 bar). This solution or this gel can then be applied to paper or cardboard for coating. After a predetermined drying time, the target substrate has a smooth surface. Here, after applying the multilayer body or the transfer layer of the multilayer body, the binarized two-dimensional Fourier pattern looks more intense and is therefore easier to read for mobile terminals.

[0085] When the multilayer body is used as a cold stamping film, a relatively thick adhesive layer can be used to compensate for surface roughness. In the case of cold stamping, the adhesive layer is first applied to the underside of the multilayer body or to the upper side of the target substrate directly before the cold stamping is applied. For this purpose, cold-hardening adhesives are preferably used, in particular UV-curing cold-hardening adhesives. The cold-hardening adhesive is preferably applied in an amount of 5 g / m 2 Up to 6g / m 2 An application weight within a range of 500 g / cm2 is applied to the target substrate and / or multilayer body.

[0086] In addition, when the multilayer body is used as a cold printing film, substrate preprinting can also be performed on the target substrate before applying the multilayer body or the transfer layer of the multilayer body. For a detailed description of substrate preprinting, reference can be made to the above statements, which also apply here.

[0087] Preferably, the first graphic code is designed to be a machine-readable code, in particular a 2D barcode, a QR code or a data matrix code. The first graphic code can also be a batch-specific code, in particular a batch number provided when reading the first graphic code.

[0088] For this purpose, preferably, a series of multilayer bodies is first divided into preferably non-overlapping batches. A batch-specific batch number is assigned to each multilayer body of the batch. Within a batch and within a master, multiple serial numbers can be used by equipping the impression cylinder and / or embossing tool with different individual serial numbers.

[0089] Therefore, it is particularly designed that the multilayer body has a second graphic code. Preferably, the second graphic code is an individual code, in particular a workpiece individual code or a series individual code, and it is particularly preferred that a serial number is provided when the second graphic code is read out. The second graphic code is preferably publicly readable. Publicly readable means that it is applied to the multilayer body so that it is read by a conventional reading algorithm, which has been downloaded to a commercially available mobile terminal such as a smartphone, which has a camera and can read out the information contained therein, such as a serial number. Publicly readable can also be understood as the meaning of the second graphic code that can be read by a person without auxiliary tools. For example, this can be a date indication or a continuous series number or a workpiece number.

[0090] Like the serial number, the batch number can be a sequence of numbers, letters, characters or a combination of these characters. The batch number and serial number are a piece of information by which a batch or individual multilayer bodies can be identified. It can also be a two-dimensional arrangement of characters or images.

[0091] The batch-specific batch number is encoded in a machine-readable batch-specific first graphical code. The individual serial number is encoded in an individual machine-readable second graphical code. The first graphical code and / or the second graphical code are preferably conventional machine-readable codes, such as 2D barcodes, in particular data matrix codes or QR codes. They can also be one-dimensional barcodes, but can also be three-dimensional codes, quick mark codes, short codes, etc. Machine-readable graphical codes usually include optoelectronically readable symbols, which consist of lines or dots of different widths and gaps between them with as high a contrast as possible.

[0092] However, the URL of the authentication server can also be stored in the second graphical code. Through this URL, the user can connect to the authentication server. Such a URL can be, for example, http: / / www.authserver.com / , and the serial number is preferably part of the URL, such as http: / / www.authserver.com / serialnumber / 12345, where 12345 is the serial number. Therefore, the consumer can connect to the authentication server via an Internet browser by scanning the machine-readable second graphical code with a smart phone.

[0093] In particular, the first graphical code, in particular the batch number, and / or the second graphical code, in particular the serial number, are designed to be stored in the authentication database of the authentication server, in particular in pairs.

[0094] Preferably, the binarized two-dimensional Fourier pattern and / or the second graphic code are read by a mobile terminal, and a data transmission connection is established between the mobile terminal and an authentication server, and an authentication software enables comparison of the data read by the mobile terminal device and transmitted to the authentication server with the read first graphic code (especially the batch number) and / or the read second graphic code (especially the serial number) stored in the authentication database.

[0095] It is particularly preferred that the second graphic code is applied in the form of a print in front of the replication layer, wherein the print is applied to the carrier layer and / or the release layer and / or the protective layer at least partially in the second area, and / or the second graphic code is applied in the form of a print behind the replication layer, wherein the print is applied to the replication layer and / or the metal layer and / or the HRI layer and / or the adhesive layer and / or the primer layer at least partially in the second area.

[0096] These two arrangements make different optical effects possible. For example, in the case of printing after the structured replication step, an embossed structure can be superimposed on the print when viewed from the carrier layer. If printing has been carried out before the structured replication step, this is not possible when viewed from the carrier layer. In the case of applications in which the multilayer body is viewed both from the carrier layer and from the side facing away from the carrier layer, in particular in the region of a window or a transparent substrate, the targeted positioning of one or more prints before the replication layer or, viewed from the carrier layer, behind the replication layer, thus makes different visual effects possible on the viewing side.

[0097] Both arrangements described above preferably offer the advantage of protecting the printed matter from external mechanical influences and manipulation attempts.

[0098] In this printing method step, a second, preferably publicly available, machine-readable graphical code is printed on the multilayer body using a digital printing method with preferably a low resolution. The machine-readable graphical code may contain at least one individual serial number as information. An individual serial number is understood here to mean a number that is used only once in a series of multilayer bodies and is therefore unique. The serial number is preferably selected from a large number range or generated in a cryptographic manner, with the result that a potential counterfeiter cannot guess a valid serial number.

[0099] Printing may be achieved by a digital printing method and may be selected from the group consisting of inkjet printing, thermal transfer printing, laser printing, laser engraving.

[0100] It is also conceivable that the print or ink is applied to a substantially smooth surface of the replication layer, in particular to a replication layer that has not yet been replicated. Here, the surface is preferably replicated at least partially at a later point in time.

[0101] The ink may be formed to be transparent, translucent, opaque, invisible, colored and / or colorless. Likewise, in principle, the print is not limited to any particular design. The print may be formed to be transparent, translucent, opaque, invisible, colored and / or colorless.

[0102] Furthermore, it is also conceivable to provide luminescent inks (transparent and colored luminescent inks), fluorescent inks (transparent and colored fluorescent inks), phosphorescent (including chemiluminescent) inks (transparent and colored phosphorescent inks) and / or liquid crystal inks (particularly with dichroic color effects) and / or laser-sensitive inks and / or inks with markers, whereby additional machine readability can be added.

[0103] Both light-curing (especially UV-curing) inks and solvent- and / or water-based inks can be used.

[0104] If a print is applied to an already copied copy layer, the corresponding copied structure is preferably weakened at this point. In the case of suitable printing varnishes and layer thicknesses of the printed layer, the copied structure can even be erased or almost erased, whereby the optical effect of the structure is locally destroyed. The surface of the printed layer formed towards the air during the printing process is preferably smooth or isotropically matte after the printed layer has dried. If a transparent print is therefore preferably used, neither the structure nor the print itself is visible, or they are almost invisible at this point. If an opaque print is preferably used, the structure is no longer visible at this point. The print appears in the corresponding color. After the metal layer has been applied to the copy layer, the area with the erased structure preferably appears as a mirror or matte surface to an observer and / or a sensor.

[0105] The thickness of the applied or printed ink layer is preferably between 0.1 μm and 30 μm, in particular between 0.5 μm and 15 μm, particularly preferably between 0.5 μm and 15 μm, advantageously between 1 μm and 8 μm. If solvent and / or water-based inks are used, the layer thickness is preferably about 0.5 μm. If UV-curable inks are used, the layer thickness is approximately between 1 μm and 30 μm, preferably between 1 μm and 15 μm, particularly preferably between 1 μm and 8 μm.

[0106] Furthermore, the replicating layer can also be replicated together with the print applied thereto.

[0107] The print can also further contain an ink, preferably a UV-curable ink, and / or the print can be poured, coated and / or encapsulated with a UV-curable replication varnish, whereby in particular initial crosslinking and / or crosslinking occurs. The initial crosslinking is not complete, but only partially crosslinked. In particular, in addition to surface crosslinking, the complete curing of the UV-curable ink can also be improved by pouring and / or encapsulating with a UV-curable replication varnish, because by crosslinking, in particular thin UV-curable layers, destructive inhibition effects, for example due to atmospheric oxygen, can be prevented. In particular, this is particularly advantageous in the case of applied UV-curable inks that are thinner than 1.5 μm, because as the thickness of the UV-curable ink layer decreases, the inhibition effects have a stronger influence or can even prevent surface and layer crosslinking to such an extent that the print or ink can remain viscous and, for example, a multilayer body that has been printed thereon cannot be wound into a roll.

[0108] In order to cure thin UV-curing layers, complex and expensive inertization measures are usually required during UV curing, especially during UV curing under protective gases such as argon or nitrogen. If printing with UV-curable inks is carried out without rolling up the multilayer body in the same production step as UV replication, these complex and expensive measures can be avoided by covering the UV-curable print with a UV-curing replication varnish downstream.

[0109] In addition, the UV drying process used in the UV replication process represents an additional post-curing of the UV print, which is effective due to the minimization of inhibition. In particular, after optional fixing (UV pre-curing), the UV curing equipment of the UV replication can also be used during the application of the UV print, without the need for additional UV curing equipment to cure the print itself.

[0110] In particular, combining the printing of UV-curable inks with a directly downstream UV replication process can enable the UV inks to be applied much thinner than would actually be possible without the complex measures dictated by the curing.

[0111] In particular, the "initial crosslinking" of the UV-curable ink or UV-curable print on the surrounding matrix of the UV replication varnish results in the print being virtually inseparably bound to the polymer surrounding. Advantageously, the print itself then no longer represents a discrete layer. This additionally makes manipulation more difficult.

[0112] It is particularly advantageous if there is the possibility of post-crosslinking of the UV-curable ink by UV-curing of the UV-curing replication varnish, which can lead to a higher stability of the UV-curing ink.

[0113] For applying UV replication to the print, in particular independently of its material composition, it is also advantageous to significantly reduce mechanical and / or thermal stresses on the print, in particular due to contact pressure or especially due to temperature, such as occurs during thermal replication.

[0114] In addition, the print is applied to the already replicated surface of the replication layer. This means that the replication layer has been provided with an embossed structure. Preferably, the ink is applied at least partially to the structured surface or embossed structure. Preferably, the deposition of the print is achieved in register with the embossed structure. Ideally, the ink is applied so that the ink only partially fills the embossed structure. Partial filling of the structure occurs especially when the thickness of the ink layer finally applied is less than the depth of the embossed structure of the binarized two-dimensional Fourier pattern. In addition, the ink can also be applied to a partial surface in the grid so that the ink only covers a partial surface area of ​​the embossed structure. The resolution of the grid is preferably lower than the resolution of the human eye, wherein adjacent grid elements (Ras terelemente) of the ink preferably have a mutual spacing in the range of 5μm to 250μm, preferably 20μm to 200μm, and / or wherein the line width and / or dot diameter and / or single element diameter of the grid element are in the range of 5μm to 250μm, preferably 20μm to 200μm.

[0115] Under certain conditions, the ink can also completely fill the embossed structure of the binarized two-dimensional Fourier pattern without being optically erased. This is particularly the case when the ink has reflective or highly refractive properties and the difference between its complex refractive index and the complex refractive index of the replication layer is in particular greater than 0.2. Examples of reflective inks are inks with metallic effect pigments or metal flakes. Examples of highly refractive inks are liquid crystal-based inks. For partial filling, in particular macroscopic structures, i.e. in particular non-diffractive active structures, also apply to the replication layer. Since the embossed structure of the binarized two-dimensional Fourier pattern is not optically erased by the print, it is ensured that all information items in the Fourier pattern are retained and can always be read and evaluated by a mobile terminal when the Fourier pattern is read out.

[0116] Preferably, the first area and the second area are arranged to be adjacent to each other or spaced apart from each other or at least partially overlap each other. Because the binarized two-dimensional Fourier pattern is arranged in the first area, and the second graphic code is arranged in the second area by printing, various creative designs can be envisioned.

[0117] For example, the binarized two-dimensional Fourier pattern can be arranged to be spaced apart from the second graphic code. However, ideally, the spacing should be selected so that the binarized two-dimensional Fourier pattern and the second graphic code can always be read simultaneously by a mobile terminal, preferably by a single acquisition. For this purpose, the resolution of the camera used is decisive.

[0118] Optionally, the binarized two-dimensional Fourier pattern and the second graphic code may also partially overlap. Thus, the second graphic code may be arranged, for example, so that a portion of the second graphic code is surrounded by the binarized two-dimensional Fourier pattern, while another portion of the second graphic code is surrounded by another background. For example, all decorative layers, such as color layers and / or metal layers and / or printed layers, are considered as backgrounds here. The other background itself may also exhibit other security features. For example, they may be diffraction structures, such as holograms or and / or matte structures and / or blazed gratings and / or computer generated holograms (CGH).

[0119] It is also conceivable that the second area is completely arranged in the first area. The second graphic code is then located within the binarized two-dimensional Fourier pattern. As already described above, the print or ink of the second graphic code is applied so that the print or ink only partially fills the embossed structure of the binarized two-dimensional Fourier pattern. All information items of the Fourier pattern are thus obtained. This arrangement provides the advantage that both the binarized two-dimensional Fourier pattern and the second graphic code can always be read by a single acquisition.

[0120] In addition, additional embossed structures can be provided in the third area or in the area where the binarized two-dimensional Fourier pattern is not present. These can be, for example, structures selected from the following and / or structures superimposed by the following, alone or in combination: light diffraction microstructures or nanostructures, light refraction microstructures or nanostructures, light focusing microstructures or nanostructures, binary or continuous Fresnel lenses, binary or continuous Fresnel free-form surfaces; diffraction macrostructures, refraction macrostructures, in particular lens structures or micro-prismatic structures, mirrors, matte structures, in particular anisotropic matte structures or isotropic matte structures, computer-generated hologram structures, blazed gratings, volume holograms, etc. This ensures a visually appealing overall impression and / or additional protection against counterfeiting.

[0121] A spatial separation of the binarized two-dimensional Fourier pattern and the additional embossed structure as well as the integration of the binarized two-dimensional Fourier pattern in at least one design element of the additional embossed structure are conceivable. Here, spatial separation preferably means the spacing between the binarized two-dimensional Fourier pattern and the additional embossed structure. The design element here preferably means a complete decorative pattern, but also an incomplete decorative pattern, i.e. a fragment of a decorative pattern. The decorative pattern can in particular be selected from images, symbols, logos, coats of arms, flags, portraits, alphanumeric characters or combinations thereof. For example, the binarized two-dimensional Fourier pattern can be integrated in the decorative pattern in order to produce a particularly high level of anti-counterfeiting protection of the multilayer body.

[0122] Furthermore, at least one glaze layer may be arranged over the entire surface or at least partially in a region or over the entire surface behind at least one first region and / or second region in the viewing direction of the observer. If the glaze layer is arranged behind the first region where the binarized two-dimensional Fourier pattern is arranged and / or behind the second region where the second graphic code is arranged, the effect of the glaze layer is preferably visible only at points where the binarized two-dimensional Fourier pattern has bright pixels and / or where the second graphic code has bright pixels (in particular white or transparent pixels).

[0123] The glaze layer can directly adjoin the metal layer or be separated from the metal layer by a dielectric intermediate layer. At least one glaze layer serves as a colored background and thus as an optical contrast region and produces a readable color impression for the observer in the corresponding color of the color layer. In addition, due to the increased contrast with the background, the reading of the binary two-dimensional Fourier pattern by a mobile terminal is also improved.

[0124] Advantageously, at least one glaze layer, in particular in the CIELAB color space, in particular in direct reflection within a tilt angle range of preferably at least 0° to 30° relative to the normal and / or within a tilt angle range of preferably at least 30° to 60° relative to the normal, has a total color difference dE with the first area and / or the second area of ​​50 to 270, preferably 100 to 270, further preferably 130 to 270.

[0125] It is also advantageous if at least one enamel layer, in particular in direct reflection within an angle range of preferably at least 0° to 30° relative to the normal and / or within an angle range of preferably at least 30° to 60° relative to the normal, has a lighter color, in particular with a higher brightness value L, and a first region and / or a second region, in particular dark pixels of the first and / or second region, in particular with a lower brightness value L. As a result, the color effect of the enamel layer can act via the light pixels, thereby further increasing the contrast between the light pixels and the dark pixels.

[0126] For the authentication, the authentication method mentioned at the outset is expediently carried out, which is preferably carried out with an authentication system. The authentication method is suitable for carrying out with one of the above-described multilayer bodies or a series of multilayer bodies produced according to one of the above-described production methods.

[0127] According to the present invention, a mobile terminal with a camera is used to perform the authentication method. The mobile terminal may be a commercially available smart phone, and the camera may be a commercially available camera integrated in the smart phone.

[0128] The image reading by the camera is usually realized as an RGB color image, in which the image is displayed in three color channels: red (0≤R≤255), green (0≤G≤255) and blue (0≤B≤255). For evaluation, the color image is converted into a grayscale image, in which the corresponding gray value of the individual pixels can be determined as the weighted sum of the color channels:

[0129] G=C R ·R+C G ·G+C B ·B

[0130] Here the coefficient C R , C G and C B Different results may be obtained depending on the sensor type and the conversion algorithm used.

[0131] Combination C is preferred R =1 / 4, C G = 1 / 2 and C B =1 / 4 (Baier sensor) or C R =C G =C B =1 / 3 (HSI model).

[0132] Contrast at this point means the maximum gray value I of the binarized two-dimensional Fourier pattern according to the following formula: max and the minimum gray value I min Calculate the value of K:

[0133]

[0134] Testing of the readout behavior showed that under ideal lighting conditions a minimum contrast ratio of K = 0.05 is required.

[0135] On the other hand, under real conditions with varying illumination qualities, a minimum contrast ratio of K = 0.1 is preferred for a robust readout process.

[0136] It is particularly preferred if the contrast K in the grayscale image of the embossed structure is in the range from 0.1 to 0.2. These two extreme values ​​are also included in the range.

[0137] As described above, the contrast of the binarized two-dimensional Fourier pattern is generated by the bright pixels and dark pixels formed by the embossed structure.

[0138] Due to the generated contrast, perfect reading of the first graphic code of the multi-layer body is possible.

[0139] In particular, when reading the image, the second graphic code of the multilayer body can also be read.

[0140] The read image is provided to a second reading algorithm for a second graphic code, and the second graphic code is read, and the read first graphic code and the read second graphic code are detected.

[0141] In addition, the batch number can be provided by reading the first graphic code, the serial number can be provided by reading the second graphic code, and the batch number and the serial number can be detected. In this process, it is preferred to detect whether the batch number and the serial number and their distribution to each other are valid.

[0142] First, batch-specific batch numbers and individual serial numbers are assigned to each other in pairs and are preferably stored in a database. Advantageously, the serial numbers are not formed continuously, but cryptographically encrypted, resulting in valid serial numbers that are not easily figured out or guessed by counterfeiters.

[0143] The read first graphic code (especially the read batch number) can also be provided to the authentication server and compared with the valid first graphic code (especially the batch number) stored on the authentication server, and if the read first graphic code (especially the batch number) matches one of the stored valid first graphic codes (especially the batch number), it is authenticated.

[0144] In addition, the read second graphic code (especially the read serial number) can be provided to the authentication server and compared with the valid second graphic code (especially the serial number) stored on the authentication server, and if the read second graphic code (especially the serial number) matches one of the stored valid second graphic codes (especially the serial number), it is authenticated.

[0145] It is particularly preferably provided that the multilayer body is authenticated if the first graphical code has been authenticated or if both the first graphical code (in particular the batch number) and the second graphical code (in particular the serial number) have been authenticated.

[0146] The multilayer body is preferably authenticated if the combination of the read-out first graphical code, in particular the batch number, and the read-out second graphical code, in particular the serial number, has been authenticated.

[0147] For this purpose, both the serial number and the batch number are stored in a database, wherein the database is connected to the authentication server in a data-conducting manner. The serial number and the batch number are compared with the serial number and the batch number stored in the database. If the two numbers match individually and in pairs, the multilayer body is authenticated. It is therefore an original multilayer body.

[0148] If the batch number or the first graphic code cannot be read, for example because it is a blurred copy of the binarized two-dimensional Fourier pattern of the multilayer body, the multilayer body is not authenticated. If the serial number or the second graphic code has been queried once or several times, then in the case of the next query, the serial number or the second graphic code is preferably no longer authenticated. The serial number or the second graphic code may preferably be queried only once or a certain number of times and then blocked or made invalid.

[0149] All or some of the Fourier inverse transform programs required for the authentication method, the first reading algorithm and / or the second reading algorithm may be provided on the mobile terminal. However, it is also conceivable that one or more of these programs are stored on the authentication server. Preferably, the database of valid batch number pairs and serial number pairs is also stored on the authentication server.

[0150] It is also checked whether the saved serial number and the saved batch number assignment match the read batch number and the read serial number assignment. If the respective numbers and the assignment match, an authentication signal is output to the mobile terminal. The connection between the mobile terminal and the database server can be realized by a conventional, preferably wireless connection, such as a WLAN connection to the Internet, a 3G / 4G / 5G connection to the Internet or a similar connection.

[0151] In particular, the authentication system mentioned at the outset is used to carry out the authentication method.

[0152] In addition, the authentication system may also have a second reading algorithm for the second graphic code, which reads the second graphic code and wherein the read first graphic code (especially the batch number) and the read second graphic code (especially the serial number) are authenticated by the authentication server.

[0153] In particular, the inverse Fourier transform program can be downloaded to the mobile terminal, but it can also be the case that the binarized two-dimensional Fourier pattern read by the camera is transmitted to the authentication server via the transceiver unit. Likewise, the first and second reading algorithms can be stored on the mobile terminal or on the database authentication server. However, it is convenient that both reading programs, like the inverse Fourier transform program, are stored on the mobile terminal, with the result that only the batch-specific batch number or the first graphic code that has been read and the individual serial number or the second graphic code that has been read need to be transmitted to the authentication server via the transceiver unit of the mobile terminal. The numbering can be transmitted with a much smaller amount of data than the Fourier pattern scanned by the camera.

[0154] In the following, the invention is explained by reference to a number of embodiment examples with the aid of the accompanying drawings. Therefore, the embodiment examples shown should not be understood as limiting.

[0155] Figure 1 Schematic diagram showing a multilayer body

[0156] Figure 2 Schematic diagram showing a multilayer body

[0157] Figure 3 Schematic diagram showing a multilayer body

[0158] Figure 4 Schematic diagram showing a multilayer body

[0159] Figure 5 Schematic diagram showing a multilayer body

[0160] Figure 6 Schematic diagram showing a multilayer body

[0161] Figure 7 Schematic diagram showing a multilayer body

[0162] Figure 8 Shows the batch number encoded as the first graphic code in the Data Matrix code

[0163] Fig. 9 The positioning of the Data Matrix code as the first graphic code in the image template is shown Fig.10a The amplitude function of the first graphic code located in the image template is shown

[0164] Fig.10b The phase function of the first graphic code located in the image template is shown

[0165] Fig.11a Shows Fig.10a and Fig.10b The Fourier pattern as the real part of the Fourier transform of the first graphic code.

[0166] Fig.11b The 50% binarization is shown in Fig.11a The Fourier pattern

[0167] Fig.11c The 20% binarization is shown Fig.11a The Fourier pattern

[0168] Fig.12a Shows Fig.11a The amplitude of the inverse Fourier transform of the Fourier pattern in

[0169] Figure 12b Shows Fig.11bThe magnitude of the inverse Fourier transform of the binarized two-dimensional Fourier pattern in

[0170] Fig.12c Shows Fig.11c The magnitude of the inverse Fourier transform of the binarized two-dimensional Fourier pattern in

[0171] Fig.13a The transfer layer of the multilayer body applied to the paper substrate is shown in a top view

[0172] Fig.13b A nickel gasket with a pressed structure is shown in the micrograph.

[0173] Figure 1 A schematic diagram of a multilayer body 1 is shown. The multilayer body 1 can be, for example, a laminating film or a transfer film. The multilayer body 1 can also be used to provide a security document with at least one security element for anti-counterfeiting protection.

[0174] exist Figure 1 In the illustration shown, the multilayer body 1 has a carrier layer 11 and a replication layer 12. A first graphic code 21 which is Fourier transformed into a binary two-dimensional Fourier pattern 24 is embedded in the replication layer 12 via an embossed structure. Figure 1 In the design of the embossed structure is designed over the entire surface. However, it is also possible to mold the embossed structure at least partially in the first region of the replication layer 12. In addition, the multilayer body 1 has a metal layer 13 applied over the embossed structure of the replication layer 12. The binarized two-dimensional Fourier pattern 24 thus exhibits optical variability. This significantly enhances the anti-counterfeiting protection of the Fourier pattern. This is because the optical variability of the Fourier pattern cannot be read by conventional copying with the aid of a commercially available copier or a combination of a commercially available camera and a commercially available printer.

[0175] The metal layer 13 is preferably formed alone or as an alloy or eutectic alloy (selected from aluminum, chromium, gold, copper, tin, indium, silver). The metal layer 13 is preferably produced by vapor deposition, in particular by vacuum vapor deposition. The vapor-deposited metal layer 13 can be realized on the entire surface and optionally remain on the entire surface, or structured by known demetallization methods (such as etching, stripping (paint washing method) or photolithography, and therefore only partially present. The layer thickness of the metal layer is particularly between 10nm and 500nm.

[0176] However, the metal layer 13 can also consist of a printed layer, in particular of a printed layer of metal pigments in a binder. These printed metal pigments can be applied to the entire surface or to a portion of the surface and / or have different colors in different areas of the surface. The layer thickness of the metal layer of metal pigments is in particular between 1 μm and 10 μm.

[0177] The metal layer 13 can also be produced from a varnish having electrically conductive metal pigments, in particular it can be printed and / or poured on.

[0178] Alternatively, an HRI or LRI layer (high refractive index - HRI, low refractive index - LRI) can also be used instead of the metal layer 13. Such a dielectric HRI or LRI layer consists of a vapor deposited layer of, for example, a metal oxide, a metal sulfide, titanium oxide, etc. The layer thickness of such a layer is preferably 10 nm to 500 nm.

[0179] In addition, according to Figure 1 The multilayer body 1 also comprises an adhesive layer 14. This adhesive layer 14 produces adhesion to the target substrate after application. Optionally, this can also be a primer layer. In this case, the adhesive layer 14 is applied to the multilayer body 1 or the target substrate before application. The primer layer increases the adhesion to the adhesive.

[0180] The adhesive layer 14 and / or the primer layer 14 are preferably formed from a varnish which is selected, alone, in a plurality of sub-layers and / or as a mixture, from the group consisting of PMMA, PVC, acrylates, polyamides, polyvinyl acetates, hydrocarbon resins, polyesters, polyurethanes, chlorinated polyolefins, polypropylenes, epoxy resins and / or polyurethane polyols, in particular in combination with non-activated isocyanates, fillers such as SiO2 and / or TiO2. The adhesive layer 14 or the primer layer 14 may also contain fillers such as SiO2 and / or TiO2. In addition to the adhesive layer, a primer layer may also be provided.

[0181] The layer thickness of the adhesive layer 14 and / or primer layer 14 is preferably between 0.5 μm and 20 μm, particularly preferably between 1.5 μm and 5 μm. The adhesive layer 14 and / or primer layer 14 can be produced by gravure printing, flexographic printing, screen printing, inkjet printing and / or by means of a slit nozzle.

[0182] Furthermore, the adhesive layer 14 or the primer layer 14 fulfills the purpose of filling the depressions in the embossed structure, thereby ensuring that the depressions and / or elevations of the embossed structure are encapsulated and thus protected from external environmental influences.

[0183] The target substrate can be, for example, a security document, in particular an identity document or a passport. However, the target substrate can also be a packaging material. However, target substrates made of cardboard or paper are also conceivable.

[0184] Figure 2 A further schematic illustration of a multilayer body 1 is shown. Figure 2 The multilayer body 1 corresponds to Figure 1 The structure of the multilayer body 1 is similar to that of the multilayer body 1 of FIG. 1 , but differs in that a release layer 15 and a protective layer 16 are arranged between the carrier layer 11 and the replication layer 12. The release layer 15 may be present on a part of the surface or on the entire surface.

[0185] The peeling layer 15 ensures in particular that the layers of the multilayer body 1 can be separated from the carrier layer 11 in a non-destructive manner. The peeling layer 15 is preferably formed of wax, polyethylene (PE), polypropylene (PP), cellulose derivatives and / or poly(organic)siloxanes. The above-mentioned wax can be a natural wax, a synthetic wax or a combination thereof. The above-mentioned wax is, for example, carnauba wax. The above-mentioned cellulose derivative is, for example, cellulose acetate (CA), cellulose nitrate (CN), cellulose acetate butyrate (CAB) or a mixture thereof. The above-mentioned poly(organic)siloxane is, for example, a silicone adhesive, a polysiloxane adhesive or a mixture thereof. The peeling layer 15 preferably has a layer thickness in the range of 1 nm to 500 nm, in particular a layer thickness in the range of 5 nm to 250 nm, and particularly preferably a layer thickness in the range of 10 nm to 250 nm.

[0186] The release layer 15 can be produced by known printing methods. In particular, gravure printing, flexographic printing, screen printing, inkjet printing or application by a slit nozzle are suitable for this. However, the release layer 15 can also be formed by vapor deposition, physical vapor deposition (PVD), chemical vapor deposition (CVD) and / or sputtering deposition.

[0187] The protective layer 16 is preferably a thermoplastic layer or a heat-cured layer or a radiation-cured layer of a varnish, which is selected from PMMA, PVC, melamine, acrylates, polyurethanes, crosslinkers, photoinitiators, additives, defoamers, leveling agents, wetting agents, etc., alone, in multiple sublayers and / or as a mixture. The protective layer can also be composed of radiation-curable dual-cured varnishes. This dual-cured varnish can be thermally pre-crosslinked in the first step during and / or after application in liquid form. Preferably, in the second step, especially after processing the multilayer film, the dual-cured varnish is radiation-post-crosslinked by high-energy radiation (preferably UV radiation). This type of dual-cured varnish can be composed of different polymers or oligomers, which have unsaturated acrylate or methacrylate groups. These functional groups can be radiation-crosslinked to each other, especially in the second step. For the thermal pre-crosslinking in the first step, it is advantageous that at least two or more alcohol groups are also present in the case of these polymers or oligomers. These alcohol groups can be crosslinked with multifunctional isocyanates or melamine formaldehyde resins. Various UV raw materials, such as epoxy acrylates, polyether acrylates, polyester acrylates and in particular acrylic acrylates are preferably suitable as unsaturated oligomers or polymers. Both blocked and unblocked representatives based on TDI (TDI = toluene-2,4-diisocyanate), HDI (HDI = hexamethylene diisocyanate) or IPDI (IPDI = isophorone diisocyanate) are suitable as isocyanates. Melamine crosslinkers can be in fully etherified form, of the imino type or as benzoguanamine representatives.

[0188] The protective layer 16 preferably has a layer thickness in the range of 50 nm to 30 μm, preferably 1 μm to 5 μm. The protective layer 16 can be produced by gravure printing, flexographic printing, screen printing, inkjet printing, or by means of a slit nozzle and / or by vapor deposition, in particular by physical vapor deposition (PVD), chemical vapor deposition (CVD) and / or sputtering deposition.

[0189] Figure 3 A further schematic diagram of a multilayer body 1 is shown in FIG. Figure 2 The multilayer body 1 is similar to the multilayer body 1 of FIG. 1 , but differs in that it additionally has at least one compensation layer 17. The compensation layer 17 can be arranged between the replication layer 12 and the adhesive layer 14 or the primer layer 14, or as Figure 3 As shown, it is arranged between the metal layer 13 and the adhesive layer 14 or the primer layer 14 .

[0190] If the multilayer body 1 is applied to a target substrate with a rough base, such as uncoated cardboard, the readout of the binarized two-dimensional Fourier pattern 24 is improved by the compensation layer 17. Tests under different light conditions have revealed that without the compensation layer 17, the readout of the Fourier pattern with a smartphone becomes more difficult.

[0191] The compensation layer 17 is preferably applied by a printing method. Gravure printing, flexographic printing, screen printing, inkjet printing or by means of a slit nozzle are preferably suitable for this. However, the compensation layer 17 can also be formed by vapor deposition, physical vapor deposition (PVD), chemical vapor deposition (CVD) and / or sputtering deposition.

[0192] Figure 4 A further schematic diagram of a multilayer body 1 is shown in FIG. The multilayer body 1 corresponds substantially to Figure 2 , but differs in that a second graphical code is applied behind the replication layer 12 in the form of a print 18, wherein the print 18 is applied to the replication layer 12 at least partially in the second region.

[0193] The embossed structure of the binarized two-dimensional Fourier pattern 24 is applied to the entire surface in the first area, wherein the first area extends over the entire surface area of ​​the multilayer body 1. The second area is arranged to overlap with the first area. Therefore, the print 18 covers the binarized two-dimensional Fourier pattern 24 in the second area.

[0194] The print 18 can be applied to the replication layer 12 which has not yet been replicated. The replication layer 12 or the replication varnish in particular still has a smooth surface. Then, in particular after the print 18 is provided, replication is performed. The embossed structure of the binarized two-dimensional Fourier pattern 24 can be introduced into the print 18 and the replication layer 12 by replication. For example, a batch-specific information item in the form of the binarized two-dimensional Fourier pattern 24 in the replication layer 12 can be combined with an individualized (in particular series-specific) print 18 in the form of a second graphic code. The replication in the print 18 can represent an additional anti-counterfeiting protection measure, because the print 18 is thus even more integrated into the overall system of the multilayer film.

[0195] Ideally, the print 18 is applied to a substantially smooth surface of the replication layer 12 or replication varnish, wherein this surface is then replicated at least partially, preferably at a later point in time.

[0196] However, the print 18 can also be applied to an already replicated replication layer 12, thus also to an embossed structure already provided with a binarized two-dimensional Fourier pattern 24. Preferably, the print 18 is applied to the embossed structure or replication layer 12 at least partially or at least in the second region.

[0197] If a print 18 is applied to an already replicated replication layer 12, at least partial areas of the embossed structure can be erased by the print 18 if it has a similar refractive index to the replication layer 12, in particular with a difference of less than 0.2. This occurs in particular when the print 18 is applied with a layer thickness greater than the depth of the structure. However, it is also possible to apply the ink with a smaller layer thickness in such a way that the print 18 follows the topology of the structure and thus in particular becomes part of the diffraction. This is conceivable in particular when using solvent inks.

[0198] Furthermore, it is also possible to apply the print 18 in such a way that the print 18 only partially fills the embossed structure on the surface of the replication layer 12. Only partial filling of the embossed structure occurs in particular when the layer thickness of the finally applied print 18 is less than the depth of the replication structure 28. Under certain conditions, the print 18 can also fill the embossed structure without being optically erased. This is particularly the case when the print 18 has reflective or highly refractive properties and the difference between its complex refractive index and the complex refractive index of the replication layer 12 is in particular greater than 0.2. Examples of reflective prints are inks with metallic effect pigments or metal flakes. Examples of highly refractive inks are inks based on liquid crystals.

[0199] The print 18 is preferably applied to the replication layer 12 with a layer thickness which is greater than the depth of the embossed structure introduced into the replication layer 12. In particular, the layer thickness of the applied print 18 is substantially twice the layer thickness of the embossed structure to be introduced into the replication layer 12. A layer thickness of the print 18 which is at least twice the depth of the structure to be introduced into the replication layer 12 is advantageous when replication is not carried out until after the application of the ink. This prevents the introduced embossed structure from completely penetrating the applied print 18 during the replication process. It is therefore ensured that the second graphical code can always be read by a machine.

[0200] In another embodiment example, the print 18 is preferably applied with a layer thickness that is less than the depth of the embossed structure to be introduced into the replication layer 12. During replication, the print 18 can thus be penetrated by the embossed structure introduced through the entire layer thickness of the print 18, whereby the print 18 can receive a high-resolution fine structure through the embossed structure that penetrates, which fine structure can also be seen from the carrier layer 11 and exceeds the printing resolution of conventional inkjet printers, thus presenting further security features.

[0201] The replication layer 12 is preferably formed from a thermoplastic varnish or a radiation-curing varnish, which is selected from the group consisting of acrylates, cellulose, PMMA, polyurethanes, isocyanates, alone, in a plurality of sub-layers and / or as a mixture. The replication layer 12 can also consist of a thermoplastic varnish. The embossed structure is preferably molded into the varnish by means of heat and pressure 18 by the action of an embossing tool. Furthermore, the replication layer 12 can also be formed from a UV-crosslinkable varnish, and the embossed structure can be molded into the replication layer 12 by UV replication. The surface structure is molded onto the uncured replication layer 12 by the action of the embossing tool, and the replication layer 12 is directly cured by irradiation with UV light during or after molding. The embossing tool can be manufactured directly or by other manufacturing stages (e.g. electroforming and / or laser engraving and / or mechanical forming), or can be used as a template for other embossing tools.

[0202] In principle, the replication layer 12 can be produced by known printing methods. In particular, gravure printing, flexographic printing, screen printing or inkjet printing are suitable. However, production by slit nozzles is also possible.

[0203] The embossed structures molded into the replication layer 12 are preferably nanostructures and / or microstructures, in particular diffraction gratings, scattering matte structures, reflective surfaces and / or reflective microstructures, which form a binarized two-dimensional Fourier pattern 24 .

[0204] The binarized two-dimensional Fourier pattern 24 is preferably formed of bright pixels 31 and dark pixels 32, which are arranged in a two-dimensional grid with a resolution of M x N pixels.

[0205] If the bright pixels 31 and the dark pixels 32 of the binarized two-dimensional Fourier pattern 24 are formed by diffraction gratings, the gratings of the bright pixels 31 and the dark pixels 32 are preferably designed to be distinguished from each other by grating period and / or grating depth and / or orientation. The grating may be a linear grating or a cross grating or a serpentine grating, or may also include more complex variations. The contour shape may be sinusoidal, blazed, or more complex. The grating period of the diffraction grating is preferably in the range of 200nm to 20μm, preferably in the range of 250nm to 10μm. In particular, the grating depth of the diffraction grating is in the range of 50nm to 2μm. In addition, the grating depth of the diffraction grating may be 5% to 20% of the grating period.

[0206] However, the bright pixels 31 and the dark pixels 32 may also be formed by structures that appear bright or dark in direct reflection, wherein the structures that appear dark include high-frequency and deep cross-grating structures and / or cross-gratings and / or hexagonal gratings and / or reflectors, and / or wherein the structures that appear bright include static and / or dynamic matte structures and / or Fourier holograms. The grating period of the cross-gratings and / or hexagonal gratings is preferably in the range of 200nm to 450nm. In addition, the grating depth of the cross-gratings and / or hexagonal gratings may be greater than 150nm. Preferably, the average spacing of the matte structures is in the range of 500nm to 5μm, and the average depth of the matte structures is in the range of 100nm to 2μm.

[0207] However, it is also conceivable that the bright pixels 31 and the dark pixels 32 are formed by blazed gratings, wherein the orientation of the blazed gratings in the bright pixels 31 and the dark pixels 32 differs by at least 150°, in particular by about 180°. The grating period of the blazed gratings is preferably in the range of 3 μm to 20 μm and / or the grating depth of the blazed gratings is in the range of 500 nm to 2 μm.

[0208] The replication layer 12 preferably has a layer thickness of between 200 nm and 5 μm. If the replication layer 12 has a diffractive surface structure, the layer thickness is preferably between 0.3 μm and 6 μm.

[0209] The replication or structuring of the surface of the replication layer 12 can be achieved in different ways. In the case of a thermoplastic replication layer 12, thermal replication is particularly achieved under the action of heat and / or pressure 18. At this point in time, a print 18, in particular a second graphic code, may have already been applied to the replication layer 12. In this case, the print 18 is applied essentially to the smooth surface of the replication layer 12.

[0210] It is also conceivable to carry out UV replication. If the print 18, in particular the second graphic code, is formed by a UV-curable ink, the UV print can advantageously be protected by a UV-curable replication varnish. The reactive groups that are "initially cross-linked" on the UV-curable replication varnish are located on the surface of the UV-curable ink. The cross-linking and thus also the stability of particularly thin prints with UV-curable inks can be improved in particular, because by encapsulating in a UV replication varnish during UV curing, the inhibitory effects that are subsequently active, especially in the case of thin UV-cured layers, are minimized. By the described encapsulation, it is also possible to achieve a smaller layer thickness of the print 18 formed with a UV-curable ink without complex and expensive inertization measures. It is also possible to reduce mechanical stress and / or thermal stress (in the case of thermal replication) caused by contact pressure.

[0211] The replication layer 12 is preferably provided with a metal layer 13 or an HRI layer with a high refractive index (HRI=High Refractive Index). The metal layer 13 and the HRI layer can be opaque, translucent or transparent, wherein in particular the transparency can depend on the viewing angle.

[0212] If it will Figure 4 As seen in FIG. 1 , the metal layer 13 covers the printed matter 18, in particular the second graphic code, over the entire surface. However, since the direction of viewing the applied multilayer body 1 is realized on the replication layer 12, the metal layer 13 forms the background of the printed matter 18 or the second graphic code.

[0213] Figure 5 A further schematic diagram of a multilayer body 1 is shown in FIG. The multilayer body 1 corresponds substantially to Figure 4 , but with the difference that the multilayer body 1 now also has a compensation layer 17. Figure 3 As described, the compensation layer 17 can be arranged between the replication layer 12 and the adhesive layer 14, or as Figure 5 As shown, the compensation layer 17 is arranged between the metal layer 13 and the adhesive layer 14. With regard to the specifications of the compensation layer 17, reference may be made to the above paragraphs.

[0214] Figure 6 Another schematic diagram of the multilayer body 1 is shown in FIG. Figure 4 The structure of the multilayer body 1 is different in that Figure 6 The print 18 or the second graphic code in is now applied in front of the replication layer 12 .

[0215] If it will Figure 6As can be seen in the figure, the print 18 is applied at least partially in the second region to the protective layer 16, wherein the protective layer 16 is preferably formed over the entire surface. This results in a multilayer body 1 in which the print 18 or the second graphic code is at least partially arranged on the protective layer 16. In particular, the print 18 is arranged below the protective layer 16 in the viewing direction and is therefore also protected by the protective layer 16 from mechanical, chemical and / or physical influences.

[0216] In an alternative design, it can be provided that the print 18 is applied to the release layer 15 at least partially in the second region, in particular wherein the release layer 15 is formed over the entire surface. Thus, a multilayer body 1 is obtained in which at least one print 18 or a second graphic code is at least partially arranged on the release layer 15.

[0217] Figure 7 Another schematic diagram of the multilayer body 1 is shown in FIG. The multilayer body 1 corresponds to Figure 6 The structure of the multilayer body 1 is different in that Figure 7 The multilayer body 1 also comprises a compensation layer 17 .

[0218] exist Figure 8 2 shows the encoding of the batch number 20 (in this case the sequence ABCDEF) as a first graphical code 21 in a data matrix code. The batch number 20 can be designed mainly according to needs and can be a sequence of letters, characters, numbers, bits or a combination thereof. Figure 8 In the data matrix code of . In the example of this embodiment, the data matrix code is a machine-readable first graphical code 21. For each multilayer body 1 in a batch, the data matrix code is the same.

[0219] The batch number 20 may also be encrypted with any other machine-readable code. Figure 8 The batch number 20 is encoded in the QR code or barcode.

[0220] The first graphic code 21 (here a data matrix code) is then preferably converted into an associated Fourier pattern. To this end, the first graphic code 21 is placed according to Fig. 9 The function is defined in the frequency plane, across which the fx frequency and the fy frequency span. Depending on where the data matrix code is located in the fx, fy plane, it is formed by higher or lower frequencies. The size of the image template is M x N pixels.

[0221] Then, the function G(fx, fy) is formed from the arrangement of the first graphic code 21 in the empty image template. The image template of M x N pixels forms the definition range of the function G(fx, fy). The function G(fx, fy) is composed of the product of the amplitude function and the phase function. Figure 8 The Data Matrix code in Fig.10a The magnitude function is represented graphically in . The magnitude function is 0 at white points and 1 or another constant value at black points. This means that the magnitude function is formed as a real-valued function with function values ​​0 and 1.

[0222] Multiply the magnitude function by the appropriate phase function Phase function It can be a random phase, but other phase distributions are also known in the prior art (Akahor i, H., Comparison of deterministic phase coding with random face coding in terms of dynamic range, Appl. Opt. 12, pp. 2336-43 (1973)). However, in the case of a random phase, a significant advantage is provided, namely that a random phase is assigned to each frequency in the image template. This makes it easier to read out the binarized two-dimensional Fourier pattern 24 later.

[0223] The phase selected here The random gray values ​​are formed into a data matrix code and are shown in Fig.10b The phase profile corresponds to the Data Matrix code, except that the values ​​are not 0 (white) and 1 (black), but random gray values ​​between white and black. In the Data Matrix code, random gray values ​​between white and black are assigned to each pixel. Now the gray values ​​are assigned to numbers between 0 and 2π. If the gray value is black, the phase is 2π, and if the gray value is white, the phase is 0. The other gray values ​​are assigned to angles between 0 and 2π depending on the gray. The darker the color, the larger the angle. In this way, the random gray image can be unambiguously converted into a phase function and by Fig.10a The graphical representation of the amplitude function is multiplied by Fig.10b The phase function in To obtain the complex-valued function G(fx,fy).

[0224] In accordance with Fig. 9A complex function G(fx,fy) is formed over a defined range of MxN pixels, where M represents the number of pixels in the fx direction and N represents the number of pixels in the fy direction. In this example, M=N=512. The complex function G(fx,fy) is Fourier transformed in a conventional manner, thereby forming a new two-dimensional complex function, i.e., a two-dimensional Fourier transform g(x,y), over M x N pixels. As an alternative to the Fourier transform, an inverse Fourier transform (inverseFouriertransformation) or an inverse Fourier transform (Fourierrücktransformation) can also be used in this method, because the symmetry conditions between the Fourier transform and the inverse Fourier transform do not lead to differences relevant to the present invention.

[0225] The real part of the Fourier transform g(x,y) is referred to herein as the two-dimensional Fourier pattern 23 and is shown at Fig.11a The two-dimensional Fourier pattern 23 is also sub-specific and has gray values ​​between white and black.

[0226] Fig.11b and Fig.11c Shows Fig.11a The Fourier pattern 23 is a so-called binarized Fourier pattern 24. Binarization means assigning a pixel value 1 or a pixel value 0 to Fig.11a Each pixel of the Fourier pattern 23 in the image is represented by a pixel value of 1. Black is used as the pixel value 1 and white is used as the pixel value 0. However, two different gray values ​​or two different color values ​​are also conceivable. For the binarization, various methods for computer-generated holograms are known from the literature, such as the detour phase method (Goodman, JW, Introduction to Fourier Optics, McGraw-Hill (New York) (1996)).

[0227] The preferred method used here is also the discrete binarization of the real part of the Fourier transform g(x,y). Here, a threshold is selected and all values ​​of the real part of the Fourier transform g(x,y) below the threshold are assigned to the pixel value 0, while all other values ​​are assigned to the pixel value 1. The threshold can be selected so that Fig.11b As shown, 50% get pixel value 1, so it is black, and 50% get pixel value 0, so it is white. Fig.11b 2 represents a 50% binarized two-dimensional Fourier pattern 24. However, the threshold value may also be chosen such that any desired other percentage receives a pixel value of 1, while the remaining pixels receive a pixel value of 0. Fig.11c A 20% binarized two-dimensional Fourier pattern 24 is shown in FIG. The percentage of binarization is preferably less than 50%, more preferably less than 20%. The binarization is usually about 15%.

[0228] Fig.11a , Fig.11b , Fig.11c The amplitudes of the inverse Fourier transforms 25 and 26 of the Fourier patterns 23 and 24 in FIG. Fig.12a , Figure 12b , Fig.12c It can be appreciated that by using the real part as the Fourier pattern, a symmetrical so-called negative sequence is formed. It can also be appreciated that binarization increases the noise (grey shades in the background), where low binarization results in greater noise. However, Fig.12a , Figure 12b , Fig.12c The inverse transformed Fourier patterns 25, 26 in each case remain machine-readable.

[0229] exist Fig.13a , the multilayer body 1 applied on a paper substrate is shown with a vertical view of the surface of the multilayer body 1 . Fig.13a The scanning resolution is 1200 dpi and the scanning is black and white. The transfer layer of the multilayer body 1 is applied to the paper substrate over the entire surface by cold stamping, and then the carrier layer 11 is separated. The binarized two-dimensional Fourier pattern 24 over the entire surface is optically variable and is therefore recognizable to an observer. Because the binarized two-dimensional Fourier pattern 24 is optically variable, it cannot be reproduced by conventional printers or copiers. Additional anti-counterfeiting protection is thus provided. GC 2 copperplate cards are used as paper substrates.

[0230] The layer structure of the applied multilayer body 1 can correspond to Figure 3 The applied transfer layer of the multilayer body 1 thus comprises, in the specified order, a protective layer 16, a replication layer 12, a metal layer 13, a compensation layer 17 and a primer layer. A binarized two-dimensional Fourier pattern 24 is molded as an embossed structure over the entire surface into a first region of the replication layer 12, which extends over the entire surface of the multilayer body 1.

[0231] exist Fig.13b A detailed view of the nickel shim used to replicate the embossed structure into Fig.13a In the replication layer 12 of the applied multi-layer body 1 . Fig.13b The cross section of the nickel gasket shown corresponds to Fig.13a The upper left corner of the binarized two-dimensional Fourier pattern 24. The total size of the cross section in the original corresponds to about 15 mm 2 The nickel shim can be used as an embossing tool or as a template for an embossing tool directly or through further manufacturing stages (such as electroplating forming and / or laser engraving and / or mechanical forming).

[0232] The bright pixels 31 and dark pixels 32 of the embossed structure are Fig.13bIt is identifiable that each pixel has a 30 μm 2 The dark pixels 32 are designed as diffraction gratings and the bright pixels 31 are designed as scattering matte structures. With this combination, a sufficiently good contrast between the bright pixels 31 and the dark pixels 32 is achieved, which can be read later by the mobile terminal and its camera.

[0233] In both lateral directions, the length of the pixel is preferably less than 45 μm, in particular less than 30 μm. The surface area of ​​the pixel is preferably less than 1800 μm. 2 , especially less than 900 μm 2 .

[0234] As has been further described above, the resolution of the binarized two-dimensional Fourier pattern 24 ensures that it is protected from copying by conventional printers and copiers. Commercially available printers generally have a printing resolution of less than 600 dpi, with the result that when the binarized two-dimensional Fourier pattern 24 is photographed and the photographed binarized two-dimensional Fourier pattern 24 is printed again, so much information is lost that it is no longer possible to reconstruct the first graphic code 21.

[0235] However, the effective resolution of the binarized two-dimensional Fourier pattern 24 is preferably greater than the equivalent printing resolution of a conventional printer, in particular greater than 600 dpi. It is further preferably designed that the binarized two-dimensional Fourier pattern has an effective resolution of at most 2500 dpi, preferably at most 1200 dpi, and particularly preferably at most 900 dpi. Such a low resolution is necessary so that the structure can actually be read by a commercially available camera by means of ordinary imaging.

[0236] Advantageously, the two-dimensional Fourier pattern 24 binarized over the entire surface is combined with at least one further optically variable nanostructure and / or microstructure. This further optically variable nanostructure and / or microstructure can take the form of additional information such as a logo, text or icon. Fine-line design elements such as guilloche are also possible. This is achieved by Fig.14 The example in FIG. 1 is represented by the letters "OK". In this example, the surface area with the letters is provided with a diffractive linear grating, whereby when tilted, the letters glow with a characteristic rainbow effect. Fig.14 In the example of, the additional optically variable nanostructures and / or microstructures preferably reduce the surface area of ​​the binarized two-dimensional Fourier pattern 24. In order to ensure reliable readout of the binarized two-dimensional Fourier pattern 24, the surface coverage of the additional optically variable nanostructures and / or microstructures (particularly relative to the total surface area of ​​the binarized two-dimensional Fourier pattern 24) is preferably less than 50%, further preferably less than 30%, and particularly preferably less than 20%.

[0237] Furthermore, it can be provided that logos, texts and / or icons are integrated in the two-dimensional Fourier pattern 24 binarized over the entire surface in such a way that they are not visible under ordinary observation and become recognizable only when tilted about the horizontal and / or vertical axis. Fig.14 Unlike the design shown, this does not result in a loss of surface area for the binarized two-dimensional Fourier pattern 24. This is achieved by Figures 15a to 15c This can preferably be achieved by locally changing the nanostructures and / or microstructures in the dark or light pixels so that although they show a dark or light appearance in ordinary observation, when tilted they have an optically variable behavior that is different from the optically variable behavior in the background of the binarized two-dimensional Fourier pattern 24.

[0238] For example, dark pixels 32 may be provided with a high frequency linear grating having a grating period of 400 nm (sub-wavelength grating) and a grating depth of 200 nm. The linear grating is preferably vapor deposited from aluminum and subsequently embedded in one or more polymer layers. The linear grating preferably absorbs a portion of incident visible light so that the pixels appear dark when viewed normally. The linear grating is preferably provided with additional information - e.g. Figures 15a to 15c The dark pixels 32 in the partial area of ​​the binarized two-dimensional Fourier pattern 24 of the letter "OK" in FIG. 1 have an azimuth angle of 0°, and the dark pixels 32 in the partial area of ​​the binarized two-dimensional Fourier pattern 24 where no additional information exists have an azimuth angle of 90°. All pixels provided with the linear grating appear dark in ordinary observation. Fig.15a This is schematically shown in the example section with reference to the partial region with the letter “O.” In the partial region, two linear gratings with azimuth angles of 0° and 90° are represented by different shading in the dark pixels 32 .

[0239] Fig.15b The entire two-dimensional Fourier pattern 24 binarized over the entire surface is now shown, in which the letters "OK" have been integrated into six areas by varying the azimuth angle of the linear grating structure in the dark pixels 32. In the present example, an azimuth angle of 0° was chosen. When tilted sharply about the horizontal axis, the letters become brighter because the first diffraction order of the subwavelength grating comes into view of the observer. On the other hand, pixels without additional information (in which a linear grating with an azimuth angle of 90° is present) do not emit light and appear dark. It is therefore easy to detect whether the binarized two-dimensional Fourier pattern 24 has been created with nanostructures and / or microstructures, or whether the binarized two-dimensional Fourier pattern 24 has been printed instead.

[0240] If the multilayer body with the two-dimensional Fourier pattern 24 binarized over the entire surface in a highly tilted state is now rotated by 90°, the pixels with the linear grating without additional information (linear sub-wavelength grating) glow brightly, while the linear grating with additional information (the letters "OK") appears dark. This change in contrast is an easily detectable security feature.

[0241] Preferably, pixels that appear dark can be better achieved by high-frequency crossed gratings. This is because linear gratings mainly absorb one polarization direction of the incident light and absorb little or no other polarization direction. On the other hand, crossed gratings are able to absorb both polarization directions. Therefore, these high-frequency crossed gratings absorb incident visible light even more efficiently than linear gratings. In the case of crossed gratings, these gratings are preferably rotated by 45° in azimuth in the partial areas with additional information compared to the partial areas without additional information. A change in contrast between brightly glowing letters on a dark background and dark letters on a light background is achieved here by a rotation of 45°.

[0242] Reference Number List

[0243] 1 Multilayer

[0244] 11 Carrier layer

[0245] 12. Duplicate Layer

[0246] 13 Metal layer

[0247] 14 Adhesive layer / primer layer

[0248] 15 Peeling layer

[0249] 16 Protective layer

[0250] 17 Compensation layer

[0251] 18 Printed Materials

[0252] 20 Batch No.

[0253] 21 First Graphic Code

[0254] 22 Empty Image Templates

[0255] 23 Two-dimensional Fourier pattern

[0256] 24 Binarized 2D Fourier pattern

[0257] 25 Inverse Fourier transform of a two-dimensional Fourier pattern

[0258] 26 Inverse Fourier transform of a binarized 2D Fourier pattern

[0259] 31 bright pixels

[0260] 32 dark pixels

Claims

1. A method for producing a multilayer body (1), in particular a laminating film or a transfer film, wherein a replication layer (12) is applied to a carrier layer (11), and The first graphic code (21) is Fourier transformed into a two-dimensional Fourier pattern (23), and the two-dimensional Fourier pattern (23) is binarized to obtain a binarized two-dimensional Fourier pattern (24), and the binarized two-dimensional Fourier pattern (24) is transferred to an embossing tool, and the binarized two-dimensional Fourier pattern (24) is molded into the replication layer (12) as an embossed structure at least partially in the first area by means of the embossing tool.

2. The method according to claim 1, It is characterized in that A release layer (15) and / or a protective layer (16) is applied to the carrier layer (11), in particular wherein the release layer (15) and / or the protective layer (16) are arranged between the carrier layer (11) and the replication layer (12).

3. The method according to claim 1, It is characterized in that A metal layer (13) and / or an HRI layer and / or a primer layer (14) and / or an adhesive layer (14) is applied to the replication layer (12).

4. The method according to claim 1, It is characterized in that The binarized two-dimensional Fourier pattern (24) is provided as a nanostructure and / or a microstructure, in particular as a diffraction grating, a scattering matte structure, a reflective surface and / or a reflective microstructure.

5. The method according to claim 1, It is characterized in that The binarized two-dimensional Fourier pattern (24) is formed by bright pixels (31) and dark pixels (32), which are arranged in a two-dimensional grid with a resolution of M×N pixels.

6. The method according to claim 5, It is characterized in that The bright pixels (31) and the dark pixels (32) are formed by diffraction gratings, wherein the gratings of the bright pixels (31) and the dark pixels (32) differ from each other by grating period and / or grating depth and / or orientation.

7. The method according to claim 6, It is characterized in that The grating period of the diffraction grating is in the range of 200 nm to 20 μm, preferably in the range of 250 nm to 10 μm, and / or the grating depth of the diffraction grating is in the range of 50 nm to 2 μm, and / or the grating depth of the diffraction grating is 5% to 20% of the grating period.

8. The method according to claim 5, It is characterized in that The bright pixels (31) and the dark pixels (32) are formed by structures that appear bright or dark in direct reflection, wherein the dark structures include high-frequency and deep cross-grating structures and / or cross-gratings and / or hexagonal gratings and / or reflectors, and / or wherein the bright structures include static and / or dynamic matte structures and / or Fourier holograms.

9. The method according to claim 8, It is characterized in that The grating period of the cross grating and / or the hexagonal grating is in the range of 200 nm to 450 nm, and the grating depth of the cross grating and / or the hexagonal grating is greater than 150 nm.

10. The method according to claim 8 or 9, It is characterized in that An average pitch of the matte structures is in a range of 500 nm to 5 μm, and an average depth of the matte structures is in a range of 100 nm to 2 μm.

11. The method according to any one of claims 5 to 7, It is characterized in that The bright pixels (31) and the dark pixels (32) are formed by blazed gratings, wherein the orientations of the blazed gratings in the bright pixels (31) and the dark pixels (32) differ by at least 150°, in particular by about 180°.

12. The method according to claim 11, It is characterized in that The grating period of the blazed grating is in the range of 3 μm to 20 μm, and / or the grating depth of the blazed grating is in the range of 500 nm to 2 μm.

13. The method according to claim 1, It is characterized in that The replication layer (12) comprises a UV-curable replication varnish which is pre-cured or fully cured by UV radiation after molding of the embossed structure.

14. The method according to claim 13, It is characterized in that Preferably after the replication varnish has cured, a metal layer (13) is applied at least partially or over the entire surface to the replication layer (12).

15. The method according to any one of the preceding claims, It is characterized in that The first graphical code (21) is a machine-readable code, in particular a 2D barcode, a QR code or a data matrix code.

16. The method according to any one of the preceding claims, It is characterized in that The first graphical code (21) is a batch-specific code, in particular in that the batch number (20) is provided when the first graphical code (21) is read.

17. The method according to any one of the preceding claims, It is characterized in that A second graphical code is applied in the form of a print (18) in front of the replication layer (12), wherein the print (18) is applied at least partially in a second region to the carrier layer (11) and / or to the release layer (15) and / or to the protective layer (16), and / or The second graphic code is applied behind the replication layer (12) in the form of a print (18), wherein the print (18) is applied at least partially in a second region to the replication layer (12) and / or the metal layer (13) and / or the HRI layer and / or the adhesive layer (14) and / or the primer layer (14).

18. The method according to claim 17, It is characterized in that The printed matter (18) is realized by a digital printing method and is selected from the following group: inkjet printing, thermal transfer printing, laser printing, laser engraving.

19. A method according to claim 17 or 18, It is characterized in that The print (18) contains an ink, preferably a UV-curable ink, and / or the print (18) is poured, coated and / or encapsulated with a UV-curable replication varnish, whereby in particular initial crosslinking and / or crosslinking occurs.

20. The method according to claim 19, It is characterized in that The application of the ink, in particular a UV-curable ink, or the provision of the print (18) is carried out in the same production step as the UV replication.

21. A method according to any one of claims 19 or 20, It is characterized in that The ink and the UV-curable replication varnish are cured together and / or the ink, in particular the UV-curable ink, undergoes post-crosslinking by UV curing of the UV-curable replication varnish.

22. The method according to any one of claims 19 to 21, It is characterized in that The ink is applied to a substantially smooth surface of the replication layer (12), in particular to a replication layer (12) which has not yet been replicated.

23. A method according to any one of claims 17 to 22, It is characterized in that The replication layer (12) is replicated together with the print (18) applied thereto.

24. A method according to any one of claims 17 to 23, It is characterized in that The print (18) is applied to the already replicated surface (18, 24) of the replication layer (12).

25. A method according to any one of claims 17 to 24, It is characterized in that The second graphical code is a machine-readable code, in particular a 2D barcode, a QR code or a data matrix code.

26. A method according to any one of claims 17 to 25, It is characterized in that The second graphical code is an individual code, in particular a workpiece-individual code or a series-individual code, particularly preferably in that a series number is provided when the second graphical code is read out.

27. A method according to any one of claims 17 to 26, It is characterized in that The URL of the authentication server is stored in the second graphic code.

28. A method according to any one of claims 17 to 27, It is characterized in that The first region and the second region are arranged adjacent to each other or spaced apart from each other or at least partially overlapping each other.

29. A method according to any one of claims 3 to 28, It is characterized in that At least one compensation layer (17) is further applied, which is preferably arranged between the replication layer (12) and the adhesive layer (14) or primer layer (14) or between the metal layer (13) and the adhesive layer (14) or primer layer (14).

30. A method according to any one of claims 17 to 29, It is characterized in that The first graphic code (21), in particular the batch number (20) and / or the second graphic code, in particular the serial number, is stored in the authentication database of the authentication server, in particular in pairs.

31. The method according to claim 30, It is characterized in that The binarized two-dimensional Fourier pattern (24) and / or the second graphic code are read by a mobile terminal, and a data transmission connection is established between the mobile terminal and the authentication server, and an authentication software enables the data read by the mobile terminal and transmitted to the authentication server to be compared with the read first graphic code (21), especially the batch number (20), and / or the read second graphic code, especially the serial number, stored in the authentication database.

32. The method according to any one of the preceding claims, It is characterized in that The binarized two-dimensional Fourier pattern is molded with an effective resolution of at most 2500 dpi, preferably at most 1200 dpi, particularly preferably at most 900 dpi.

33. A multilayer body (1), in particular a laminating film or a transfer film, which is preferably produced according to a method according to one of claims 1 to 32, It is characterized in that The multilayer body (1) comprises a carrier layer (11) and a replication layer (12) arranged thereon. An embedded first graphic code (21) which is Fourier transformed into a binarized two-dimensional Fourier pattern (24) is molded as an embossed structure at least partially in the first region into the replication layer (12).

34. The multilayer body (1) according to claim 33, It is characterized in that A release layer (15) and / or a protective layer (16) is arranged between the carrier layer (11) and the replication layer (12).

35. The multilayer body (1) according to claim 33 or 34, It is characterized in that A metal layer (13) and / or an HRI layer and / or a primer layer (14) and / or an adhesive layer (14) are arranged on the replication layer (12).

36. The multilayer body (1) according to claim 33, It is characterized in that The binarized two-dimensional Fourier pattern (24) is molded into the replication layer (12) as a nanostructure and / or microstructure, in particular as a diffraction grating, a scattering matte structure, a reflective surface and / or a reflective microstructure.

37. The multilayer body (1) according to claim 33, It is characterized in that The binarized two-dimensional Fourier pattern (24) is formed by bright pixels (31) and dark pixels (32), which are arranged in a two-dimensional grid with a resolution of M x N pixels.

38. The multilayer body (1) according to claim 37, It is characterized in that The bright pixels (31) and the dark pixels (32) are formed by diffraction gratings, wherein the gratings of the bright pixels (31) and the dark pixels (32) differ from each other by grating period and / or grating depth and / or orientation.

39. The multilayer body (1) according to claim 38, It is characterized in that The grating period of the diffraction grating is in the range of 200 nm to 20 μm, preferably in the range of 250 nm to 10 μm, and / or the grating depth of the diffraction grating is in the range of 50 nm to 2 μm, and / or the grating depth of the diffraction grating is 5% to 20% of the grating period.

40. The multilayer body (1) according to claim 37, It is characterized in that The bright pixels (31) and dark pixels (32) are formed by structures that appear bright or dark in direct reflection, wherein the dark structures include high-frequency and deep cross-grating structures and / or cross-gratings and / or hexagonal gratings and / or reflectors, and / or wherein the bright structures include static and / or dynamic matte structures and / or Fourier holograms.

41. The multilayer body (1) according to claim 40, It is characterized in that The grating period of the cross grating and / or the hexagonal grating is in the range of 200 nm to 450 nm, and the grating depth of the cross grating and / or the hexagonal grating is greater than 150 nm.

42. The multilayer body (1) according to claim 40 or 41, It is characterized in that The average pitch of the matte structures is in the range of 500 nm to 5 μm, and the average depth of the matte structures is in the range of 100 nm to 2 μm.

43. The multilayer body (1) according to claim 37, It is characterized in that The bright pixels (31) and the dark pixels (32) are formed by blazed gratings, wherein the orientations of the blazed gratings in the bright pixels (31) and the dark pixels (32) differ by at least 150°, in particular by about 180°.

44. The multilayer body (1) according to claim 43, It is characterized in that The grating period of the blazed grating is in the range of 3 μm to 20 μm, and / or the grating depth of the blazed grating is in the range of 500 nm to 2 μm.

45. The multilayer body according to claim 33 , It is characterized in that The first graphical code (21) is a machine-readable code, in particular a 2D barcode, a QR code or a data matrix code.

46. ​​The multilayer body according to claim 33, It is characterized in that The first graphical code (21) is a batch-specific code which, when read out, in particular provides the batch number (20).

47. The multilayer body (1) according to claim 33, It is characterized in that A second graphical code is applied in the form of a print (18) in front of the replication layer (12), wherein the print (18) is applied at least partially in a second region to the carrier layer (11) and / or to the release layer (15) and / or to the protective layer (16), and / or The second graphic code is applied behind the replication layer (12) in the form of a print (18), wherein the print (18) is applied at least partially in a second region to the replication layer (12) and / or the metal layer (13) and / or the HRI layer and / or the adhesive layer (14) and / or the primer layer (14).

48. The multilayer body (1) according to claim 47, It is characterized in that The second graphical code is a machine-readable code, in particular a 2D barcode, a QR code or a data matrix code.

49. The multilayer body (1) according to claim 47 or 48, It is characterized in that The second graphic code is an individual code, in particular a workpiece individual code or a series individual code.

50. The multilayer body (1) according to claim 47, It is characterized in that The first region and the second region are arranged adjacent to each other or spaced apart from each other or at least partially overlapping each other.

51. The multilayer body (1) according to claim 35, It is characterized in that The multilayer body (1) has at least one compensation layer (17), which is preferably arranged between the replication layer (12) and the adhesive layer (14) or between the metal layer (13) and the adhesive layer (14).

52. The multilayer body according to claim 33 , It is characterized in that The binarized two-dimensional Fourier pattern has an effective resolution of at most 2500 dpi, preferably at most 1200 dpi, particularly preferably at most 900 dpi.

53. A method for authenticating a multi-layer body (1) using an authentication system, in particular a multi-layer body according to one of claims 33 to 52, particularly preferably a multi-layer body produced using a method according to one of claims 1 to 32, The method comprises reading an image of a binarized two-dimensional Fourier pattern (24) of the multilayer body (1) by using a camera of a mobile terminal. Performing an inverse Fourier transform on the read image and The inverse Fourier transformed image is provided to a first reading algorithm of a first graphic code (21) And reading out the first graphic code (21) and detecting the first graphic code (21).

54. The method according to claim 53, It is characterized in that When the image is read, the second graphic code of the multilayer body (1) is also read. The read image is provided to a second reading algorithm for the second graphic code, and the second graphic code is read, and the read first graphic code (21) and the second read graphic code are detected.

55. A method according to claim 53 or 54, It is characterized in that The batch number (20) is provided by reading the first graphic code (21), and the serial number is provided by reading the second graphic code, and the batch number (20) and the serial number are detected.

56. A method according to any one of claims 53 to 55, It is characterized in that The read first graphic code (21), in particular the read batch number (20), is provided to an authentication server and compared with a valid first graphic code (21), in particular the batch number (20), stored on the authentication server, and is authenticated when the read first graphic code (21), in particular the batch number (20), matches one of the stored valid first graphic codes (21), in particular the batch number (20).

57. A method according to any one of claims 54 to 56, It is characterized in that The read second graphic code, especially the read serial number, is provided to the authentication server and compared with a valid second graphic code, especially a serial number, stored on the authentication server, and is authenticated if the read second graphic code, especially the serial number, matches one of the stored valid second graphic codes, especially the serial number.

58. A method according to any one of claims 54 to 57, It is characterized in that When the first graphic code (21) has been authenticated, or when both the first graphic code (21), in particular the batch number (20), and the second graphic code, in particular the serial number, have been authenticated, the multilayer body (1) is authenticated.

59. A method according to any one of claims 54 to 58, It is characterized in that When the combination of the read-out first graphic code (21), in particular the batch number (20), and the read-out second graphic code, in particular the serial number, has been authenticated, the multilayer body (1) is authenticated.

60. An authentication system for authenticating a multilayer body (1) according to one of claims 33 to 52, in particular a multilayer body produced by a method according to one of claims 1 to 32, - comprising a mobile terminal with a camera and a transceiver unit, wherein the mobile terminal with a camera is used to read an image of a binarized two-dimensional Fourier pattern (24) of a multilayer body (1) protected against counterfeiting, and the transceiver unit can transmit the data of the multilayer body (1) read by the camera to an authentication server, - an inverse Fourier transform program, by means of which the binarized two-dimensional Fourier pattern (24) can be inversely Fourier transformed, - a first reading algorithm for a first graphic code (21), said first graphic code being read out from said inverse Fourier transformed image, - comprising an authentication server, the authentication server being in data transmission connection with the mobile terminal, and the authentication server storing the read first graphic code (21), in particular the batch number (20), placed on the multilayer body (1), and the authentication server being capable of authenticating the read first graphic code (21), in particular the batch number (20), transmitted by the mobile terminal, and the authentication server being capable of outputting an authentication signal to the mobile terminal.

61. An authentication system according to claim 60, It is characterized in that The authentication system also has a second reading algorithm for the second graphic code, which reads the second graphic code, and wherein the read first graphic code (21), in particular the batch number (20), and the read second graphic code, in particular the serial number, are authenticated by the authentication server.

Images